Supersonic in ground effect - Revision history

Michel Lamontagne at 20:54, 10 November 2020

2020-11-10T20:54:41Z

← Older revision		Revision as of 21:54, 10 November 2020
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	==Landing at supersonic speeds==		==Landing at supersonic speeds==
	However, landing on Mars, compared to landing on Earth or landing on Luna are significantly different problems. Landing on Earth requires very little energy as the thick atmosphere an be used to slow down the ship. Landing on the moon, as there is no atmosphere, is exactly like taking off from the moon. Landing on Mars is a special problem, with just enough atmosphere to help slow down a vehicle, but not quite enough. In fact, the landing velocities of a martian shuttle depending only on aerodynamic breaking would be supersonic. In most cases, this means a crash. Landing on Mars the same way we land on the moon, with propulsive landing, requires a lot of fuel. However, it might be possible to land at very high velocities if supersonic ground effect and corresponding lifting forces could be known, since there is some atmosphere on Mars.		However, [[Landing on Mars\|landing on Mars]], compared to landing on Earth or landing on Luna are significantly different problems. Landing on Earth requires very little energy as the thick atmosphere an be used to slow down the ship. Landing on the moon, as there is no atmosphere, is exactly like taking off from the moon. Landing on Mars is a special problem, with just enough atmosphere to help slow down a vehicle, but not quite enough. In fact, the landing velocities of a martian shuttle depending only on aerodynamic breaking would be supersonic. In most cases, this means a crash. Landing on Mars the same way we land on the moon, with propulsive landing, requires a lot of fuel. However, it might be possible to land at very high velocities if supersonic ground effect and corresponding lifting forces could be known, since there is some atmosphere on Mars.

	Supersonic ground effects at landing is very likely to be a significant problem. However, if it can be solved, this might result in an economy for a Mars surface to Mars orbit shuttle. Some elements of the problem can be found in the following list:		Supersonic ground effects at landing is very likely to be a significant problem. However, if it can be solved, this might result in an economy for a Mars surface to Mars orbit shuttle. Some elements of the problem can be found in the following list:

Michel Lamontagne at 20:54, 10 November 2020

2020-11-10T20:54:14Z

← Older revision		Revision as of 21:54, 10 November 2020
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	{{Under Development}}		{{Under Development}}

	===Mars to Luna ~~Transport~~===		===Mars to Luna Transportation===
	The cost of lifting items from Mars surface to orbit should be considerably less than the cost of lifting them from Earth. This is due to the fact that since Mars' gravity is lower, the energy required to reach orbit is lower. When expressed in terms of velocity change required to reach orbit (deltaV) the values are:		Mars has a low [[Space access\|space access]] cost. The cost of lifting items from Mars surface to orbit should be considerably less than the cost of lifting them from Earth. This is due to the fact that since Mars' gravity is lower, the energy required to reach orbit is lower. When expressed in terms of velocity change required to reach orbit (deltaV) the values are:
	{\| class="wikitable"		{\| class="wikitable"
	\|+		\|+

Michel Lamontagne: /* Criticism */

2019-06-06T12:52:06Z

Criticism

← Older revision		Revision as of 13:52, 6 June 2019
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	*The landing field would need to be extremely long. The cost of this landing infrastructure might cancel out the gains in propellant savings.		*The landing field would need to be extremely long. The cost of this landing infrastructure might cancel out the gains in propellant savings.
	*The suggested wind tunnel would be extremely costly and difficult to operate. Creating a vacuum in a km long structure is difficult. However, this might be just the thing for the Boring Company.		*The suggested wind tunnel would be extremely costly and difficult to operate. Creating a vacuum in a km long structure is difficult. However, this might be just the thing for the Boring Company.
	*Supersonic retro propulsion may solve the landing problem, allowing for a ~~mars~~ landing with low propellant requirements.		*Supersonic retro propulsion may solve the landing problem, allowing for a Mars landing with large payloads and low propellant requirements.

	==references==		==references==

Michel Lamontagne: /* Criticism */

2019-06-06T12:51:32Z

Criticism

← Older revision		Revision as of 13:51, 6 June 2019
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	==Criticism==		==Criticism==

	*The vehicle would need to ~~break~~ after the landing to eventually stop. This would require systems capable of dissipating gigantic amounts of heat in the landing gear.		*The vehicle would need to slow down after the landing to eventually stop. This would require systems capable of dissipating gigantic amounts of heat in the landing gear.
	*The landing field would need to be extremely long. The cost of this landing infrastructure might cancel out the gains in propellant savings.		*The landing field would need to be extremely long. The cost of this landing infrastructure might cancel out the gains in propellant savings.
	*The suggested wind tunnel would be extremely costly and difficult to operate. Creating a vacuum in a km long structure is difficult. However, this might be just the thing for the Boring Company.		*The suggested wind tunnel would be extremely costly and difficult to operate. Creating a vacuum in a km long structure is difficult. However, this might be just the thing for the Boring Company.

Michel Lamontagne: /* Mars to Luna Transport */

2019-05-10T20:14:24Z

Mars to Luna Transport

← Older revision		Revision as of 21:14, 10 May 2019
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	\|-		\|-
	\|Earth		\|Earth
	\|		\|10 000
	\|		\|3400
	\|		\|19
	\|-		\|-
	\|Mars		\|Mars
	\|		\|3800
	\|		\|3400
	\|		\|3
	\|-		\|-
	\|Moon		\|Moon
	\|		\|1800
	\|		\|3400
	\|		\|1,7
	\|}		\|}
	DeltaV = Ve*ln(Mo/Mf).		DeltaV = Ve*ln(Mo/Mf) or M0/mf=e(DeltaV/ve)

	~~Low Mars orbit~~, ~~at an altitude~~ of ~~100 miles~~, ~~has a velocity~~ of ~~3440 meters per second~~, ~~less~~ than ~~half of~~ the ~~velocity needed to orbit~~ Earth ~~at that altitude, more than twice the velocity needed to orbit Luna~~.		With reusable rockets using liquid methane and liquid oxygen, the propellant must mass 19 times the mass of the rocket and payload to lift off from Earth. This goes down to 3 for Mars and 1,7 for the moon. This might favor some kind of transportation system between the Moon and Mars, rather than between the Earth and Mars.

	With reusable rockets built on Earth to use liquid methane and liquid oxygen, if the exhaust velocity is 3500 meters per second, there should be 36% of the take-off weight in orbit. With wings for a supersonic in ground effect landing in the 0.1 psi Martian [[atmosphere]], the empty weight should be held to 30% leaving 6% of the take-off weight as cargo.		==Landing at supersonic speeds==
			However, landing on Mars, compared to landing on Earth or landing on Luna are significantly different problems. Landing on Earth requires very little energy as the thick atmosphere an be used to slow down the ship. Landing on the moon, as there is no atmosphere, is exactly like taking off from the moon. Landing on Mars is a special problem, with just enough atmosphere to help slow down a vehicle, but not quite enough. In fact, the landing velocities of a martian shuttle depending only on aerodynamic breaking would be supersonic. In most cases, this means a crash. Landing on Mars the same way we land on the moon, with propulsive landing, requires a lot of fuel. However, it might be possible to land at very high velocities if supersonic ground effect and corresponding lifting forces could be known, since there is some atmosphere on Mars.
	== Landing at supersonic speeds ==
	However, landing on Mars, compared to landing on Earth or landing on Luna are significantly different problems. Landing on Earth requires very little energy as the thick atmosphere an be used to slow down the ship. Landing on the moon, as there is no atmosphere, is exactly like taking off from the moon. Landing on Mars is a special problem, with just enough atmosphere to help slow down a vehicle, but not quite enough ~~in many cases~~, so the landing velocities of a martian shuttle depending only on aerodynamic breaking would be supersonic. In most cases this means a crash. However, it might be possible to land at ~~these~~ velocities if supersonic ground effect and corresponding lifting forces could be known.

	Supersonic ground effects at landing is very likely to be a significant problem. However, if it can be solved, this might result in an economy for a Mars surface to Mars orbit shuttle. Some elements of the problem can be found in the following list:		Supersonic ground effects at landing is very likely to be a significant problem. However, if it can be solved, this might result in an economy for a Mars surface to Mars orbit shuttle. Some elements of the problem can be found in the following list:

	* Donald Campbell was killed on the 4th of January, 1967 when the "Bluebird K7" racing boat flipped over and disintegrated at a speed greater than 300 mph. <ref>Bluebird K7 article at Wikipedia </ref> The problem seems to have been longitudinal instability when high ground effect lifting forces acted on a center of lift that shifted rapidly with changing attitude. This sort of problem is made more difficult by the need to consider the reflection of shock waves from supersonic flight in the ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref>http://www.speedace.info/thrust_ssc </ref>		*Donald Campbell was killed on the 4th of January, 1967 when the "Bluebird K7" racing boat flipped over and disintegrated at a speed greater than 300 mph. <ref>Bluebird K7 article at Wikipedia </ref> The problem seems to have been longitudinal instability when high ground effect lifting forces acted on a center of lift that shifted rapidly with changing attitude. This sort of problem is made more difficult by the need to consider the reflection of shock waves from supersonic flight in the ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref>http://www.speedace.info/thrust_ssc </ref>

	*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. A low pressure wind tunnel, operating at 600 Pa (0.1 psi) of carbon dioxide would be needed for a simulation.		*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. A low pressure wind tunnel, operating at 600 Pa (0.1 psi) of carbon dioxide would be needed for a simulation.
Line 44:		Line 42:
	*Landing at a speed in the neighborhood of 1000 mph (450 meters per second or mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and orientation stability are problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.		*Landing at a speed in the neighborhood of 1000 mph (450 meters per second or mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and orientation stability are problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.

	== Criticism ==		==Criticism==

	* The vehicle would need to break after the landing to eventually stop. This would require systems capable of dissipating gigantic amounts of heat.		*The vehicle would need to break after the landing to eventually stop. This would require systems capable of dissipating gigantic amounts of heat in the landing gear.
	* The landing field would need to be extremely long. The cost of this landing infrastructure might cancel out the gains in propellant savings.		*The landing field would need to be extremely long. The cost of this landing infrastructure might cancel out the gains in propellant savings.
	* The suggested wind tunnel would be extremely costly and difficult to operate. Creating a vacuum in a km long structure is difficult. However, this might be just the thing for the Boring ~~company~~.		*The suggested wind tunnel would be extremely costly and difficult to operate. Creating a vacuum in a km long structure is difficult. However, this might be just the thing for the Boring Company.
	* Supersonic retro propulsion may solve the landing problem.		*Supersonic retro propulsion may solve the landing problem, allowing for a mars landing with low propellant requirements.

	==references==		==references==

Michel Lamontagne at 20:03, 10 May 2019

2019-05-10T20:03:15Z

← Older revision		Revision as of 21:03, 10 May 2019
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	{\| class="wikitable"		{\| class="wikitable"
	\|+		\|+
			Reaching orbit
	!		!
	!DeltaV to orbit (m/s)		!DeltaV to orbit (m/s)
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	\|		\|
	\|}		\|}
	DeltaV = Ve*ln(Mo/Mf).		DeltaV = Ve*ln(Mo/Mf).

	Low Mars orbit, at an altitude of 100 miles, has a velocity of 3440 meters per second, less than half of the velocity needed to orbit Earth at that altitude, more than twice the velocity needed to orbit Luna.		Low Mars orbit, at an altitude of 100 miles, has a velocity of 3440 meters per second, less than half of the velocity needed to orbit Earth at that altitude, more than twice the velocity needed to orbit Luna.

	With reusable rockets built on Earth to use liquid methane and liquid oxygen, if the exhaust velocity is 3500 meters per second, there should be 36% of the take-off weight in orbit. With wings for a supersonic in ground effect landing in the 0.1 psi Martian [[atmosphere]], the empty weight should be held to 30% leaving 6% of the take-off weight as cargo.		With reusable rockets built on Earth to use liquid methane and liquid oxygen, if the exhaust velocity is 3500 meters per second, there should be 36% of the take-off weight in orbit. With wings for a supersonic in ground effect landing in the 0.1 psi Martian [[atmosphere]], the empty weight should be held to 30% leaving 6% of the take-off weight as cargo.

	*There seems reason to ~~believe that~~ supersonic in ground effect landing is a significant problem, ~~and that~~ it ~~should yield to the proper effort~~, ~~resulting~~ in an ~~economic~~ Mars surface to Mars orbit shuttle. Donald Campbell was killed on the 4th of January, 1967 when the "Bluebird K7" racing boat flipped over and disintegrated at a speed greater than 300 mph. <ref>Bluebird K7 article at Wikipedia </ref> The problem seems to have been longitudinal instability when high ground effect lifting forces acted on a center of lift that shifted rapidly with changing attitude.		== Landing at supersonic speeds ==
	*This sort of problem is made more difficult by the need to consider the reflection of shock waves in supersonic flight in ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref>http://www.speedace.info/thrust_ssc </ref>		However, landing on Mars, compared to landing on Earth or landing on Luna are significantly different problems. Landing on Earth requires very little energy as the thick atmosphere an be used to slow down the ship. Landing on the moon, as there is no atmosphere, is exactly like taking off from the moon. Landing on Mars is a special problem, with just enough atmosphere to help slow down a vehicle, but not quite enough in many cases, so the landing velocities of a martian shuttle depending only on aerodynamic breaking would be supersonic. In most cases this means a crash. However, it might be possible to land at these velocities if supersonic ground effect and corresponding lifting forces could be known.
	*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. ~~At least with only~~ 0.1 psi of carbon dioxide needed for a simulation~~, it would not cost as much as otherwise to fill the wind tunnel with cold carbon dioxide~~.
	*An alternate wind tunnel design would be a torus or ~~hollow donut~~ shaped wind tunnel ~~to be~~ made with ~~the donut hole having~~ a one kilometer radius. It should contain a ring in a track along the wall closest to the center of the ~~donut hole~~. This ring ~~should~~ be electrically accelerated to 450 meters per second and supported in its track by a film of high-pressure carbon dioxide. Model aircraft ~~can~~ be supported in such a wind tunnel by this ring and experience the effects of supersonic ground effect. The radial acceleration needed to hold the models in circular motion would be 20.7 gravities. The portion of the ring not supporting the models would be weighted to balance loading radially with respect to the center of the ~~donut hole~~. Gas added to the wind tunnel by the carbon dioxide bearings would be removed by vacuum pumps.		Supersonic ground effects at landing is very likely to be a significant problem. However, if it can be solved, this might result in an economy for a Mars surface to Mars orbit shuttle. Some elements of the problem can be found in the following list:
	*Landing at a speed in the neighborhood of 1000 mph (450 meters per second or mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and ~~orientational~~ stability are ~~the~~ problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.
			* Donald Campbell was killed on the 4th of January, 1967 when the "Bluebird K7" racing boat flipped over and disintegrated at a speed greater than 300 mph. <ref>Bluebird K7 article at Wikipedia </ref> The problem seems to have been longitudinal instability when high ground effect lifting forces acted on a center of lift that shifted rapidly with changing attitude. This sort of problem is made more difficult by the need to consider the reflection of shock waves from supersonic flight in the ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref>http://www.speedace.info/thrust_ssc </ref>

			*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. A low pressure wind tunnel, operating at 600 Pa (0.1 psi) of carbon dioxide would be needed for a simulation.
			*An alternate wind tunnel design would be a torus (donut) or shaped wind tunnel, made with a one kilometer radius. It should contain a ring in a track along the wall closest to the center of the torus. This ring would be electrically accelerated to 450 meters per second and supported in its track by a film of high-pressure carbon dioxide. Model aircraft could be supported in such a wind tunnel by this ring and experience the effects of supersonic ground effect. The radial acceleration needed to hold the models in circular motion would be 20.7 gravities. The portion of the ring not supporting the models would be weighted to balance loading radially with respect to the center of the torus. Gas added to the wind tunnel by the carbon dioxide bearings would be removed by vacuum pumps.
			*Landing at a speed in the neighborhood of 1000 mph (450 meters per second or mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and orientation stability are problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.

			== Criticism ==

			* The vehicle would need to break after the landing to eventually stop. This would require systems capable of dissipating gigantic amounts of heat.
			* The landing field would need to be extremely long. The cost of this landing infrastructure might cancel out the gains in propellant savings.
			* The suggested wind tunnel would be extremely costly and difficult to operate. Creating a vacuum in a km long structure is difficult. However, this might be just the thing for the Boring company.
			* Supersonic retro propulsion may solve the landing problem.

	==references==		==references==

Michel Lamontagne: /* Mars to Luna Transport */

2019-05-10T19:43:32Z

Mars to Luna Transport

← Older revision		Revision as of 20:43, 10 May 2019
Line 3:		Line 3:

	===Mars to Luna Transport===		===Mars to Luna Transport===
	The cost of lifting items from Mars ~~could become~~ considerably less than the cost of lifting them from Earth. Low Mars orbit, at an altitude of 100 miles, has a velocity of 3440 meters per second, less than half of the velocity needed to orbit Earth at that altitude, more than twice the velocity needed to orbit Luna. With reusable rockets built on Earth to use liquid methane and liquid oxygen, if the exhaust velocity is 3500 meters per second, there should be 36% of the take-off weight in orbit. With wings for a supersonic in ground effect landing in the 0.1 psi Martian [[atmosphere]], the empty weight should be held to 30% leaving 6% of the take-off weight as cargo.		The cost of lifting items from Mars surface to orbit should be considerably less than the cost of lifting them from Earth. This is due to the fact that since Mars' gravity is lower, the energy required to reach orbit is lower. When expressed in terms of velocity change required to reach orbit (deltaV) the values are:
	*There seems reason to believe that supersonic in ground effect landing is a significant problem, and that it should yield to the proper effort, resulting in an economic Mars surface to Mars orbit shuttle. Donald Campbell was killed on the 4th of January, 1967 when the "Bluebird K7" racing boat flipped over and disintegrated at a speed greater than 300 mph. <ref> Bluebird K7 article at Wikipedia </ref> The problem seems to have been longitudinal instability when high ground effect lifting forces acted on a center of lift that shifted rapidly with changing attitude.		{\| class="wikitable"
	*This sort of problem is made more difficult by the need to consider the reflection of shock waves in supersonic flight in ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref> http://www.speedace.info/thrust_ssc </ref>		\|+
	*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. At least with only 0.1 psi of carbon dioxide needed for a simulation, it would not cost as much as otherwise to fill the wind tunnel with cold carbon dioxide.		!
	* An alternate wind tunnel design would be a torus or hollow donut shaped wind tunnel to be made with the donut hole having a one kilometer radius. It should contain a ring in a track along the wall closest to the center of the donut hole. This ring should be electrically accelerated to 450 meters per second and supported in its track by a film of high-pressure carbon dioxide. Model aircraft can be supported in such a wind tunnel by this ring and experience the effects of supersonic ground effect. The radial acceleration needed to hold the models in circular motion would be 20.7 gravities. The portion of the ring not supporting the models would be weighted to balance loading radially with respect to the center of the donut hole. Gas added to the wind tunnel by the carbon dioxide bearings would be removed by vacuum pumps.		!DeltaV to orbit (m/s)
			!Exhaust velocity (m/s)
			!Mass ratio Mo/mf
			\|-
			\|Earth
			\|
			\|
			\|
			\|-
			\|Mars
			\|
			\|
			\|
			\|-
			\|Moon
			\|
			\|
			\|
			\|}
			DeltaV = Ve*ln(Mo/Mf).
			Low Mars orbit, at an altitude of 100 miles, has a velocity of 3440 meters per second, less than half of the velocity needed to orbit Earth at that altitude, more than twice the velocity needed to orbit Luna.

			With reusable rockets built on Earth to use liquid methane and liquid oxygen, if the exhaust velocity is 3500 meters per second, there should be 36% of the take-off weight in orbit. With wings for a supersonic in ground effect landing in the 0.1 psi Martian [[atmosphere]], the empty weight should be held to 30% leaving 6% of the take-off weight as cargo.

			*There seems reason to believe that supersonic in ground effect landing is a significant problem, and that it should yield to the proper effort, resulting in an economic Mars surface to Mars orbit shuttle. Donald Campbell was killed on the 4th of January, 1967 when the "Bluebird K7" racing boat flipped over and disintegrated at a speed greater than 300 mph. <ref>Bluebird K7 article at Wikipedia </ref> The problem seems to have been longitudinal instability when high ground effect lifting forces acted on a center of lift that shifted rapidly with changing attitude.
			*This sort of problem is made more difficult by the need to consider the reflection of shock waves in supersonic flight in ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref>http://www.speedace.info/thrust_ssc </ref>
			*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. At least with only 0.1 psi of carbon dioxide needed for a simulation, it would not cost as much as otherwise to fill the wind tunnel with cold carbon dioxide.
			*An alternate wind tunnel design would be a torus or hollow donut shaped wind tunnel to be made with the donut hole having a one kilometer radius. It should contain a ring in a track along the wall closest to the center of the donut hole. This ring should be electrically accelerated to 450 meters per second and supported in its track by a film of high-pressure carbon dioxide. Model aircraft can be supported in such a wind tunnel by this ring and experience the effects of supersonic ground effect. The radial acceleration needed to hold the models in circular motion would be 20.7 gravities. The portion of the ring not supporting the models would be weighted to balance loading radially with respect to the center of the donut hole. Gas added to the wind tunnel by the carbon dioxide bearings would be removed by vacuum pumps.
	*Landing at a speed in the neighborhood of 1000 mph (450 meters per second or mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and orientational stability are the problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.		*Landing at a speed in the neighborhood of 1000 mph (450 meters per second or mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and orientational stability are the problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.

	==references==		==references==
	<references/>		<references />

	[[Category:Settlement Transport Systems]]		[[Category:Settlement Transport Systems]]

Jburk at 20:05, 17 December 2018

2018-12-17T20:05:31Z

← Older revision		Revision as of 21:05, 17 December 2018
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	==references==		==references==
	<references/>		<references/>

			[[Category:Settlement Transport Systems]]

Farred: addition

2010-08-02T23:35:58Z

addition

← Older revision		Revision as of 00:35, 3 August 2010
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	*There seems reason to believe that supersonic in ground effect landing is a significant problem, and that it should yield to the proper effort, resulting in an economic Mars surface to Mars orbit shuttle. Donald Campbell was killed on the 4th of January, 1967 when the "Bluebird K7" racing boat flipped over and disintegrated at a speed greater than 300 mph. <ref> Bluebird K7 article at Wikipedia </ref> The problem seems to have been longitudinal instability when high ground effect lifting forces acted on a center of lift that shifted rapidly with changing attitude.		*There seems reason to believe that supersonic in ground effect landing is a significant problem, and that it should yield to the proper effort, resulting in an economic Mars surface to Mars orbit shuttle. Donald Campbell was killed on the 4th of January, 1967 when the "Bluebird K7" racing boat flipped over and disintegrated at a speed greater than 300 mph. <ref> Bluebird K7 article at Wikipedia </ref> The problem seems to have been longitudinal instability when high ground effect lifting forces acted on a center of lift that shifted rapidly with changing attitude.
	*This sort of problem is made more difficult by the need to consider the reflection of shock waves in supersonic flight in ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref> http://www.speedace.info/thrust_ssc </ref>		*This sort of problem is made more difficult by the need to consider the reflection of shock waves in supersonic flight in ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref> http://www.speedace.info/thrust_ssc </ref>
	*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. At least with only 0.1 psi of carbon dioxide needed for a simulation, it would not cost as much as otherwise to fill the wind tunnel with cold carbon dioxide.		*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. At least with only 0.1 psi of carbon dioxide needed for a simulation, it would not cost as much as otherwise to fill the wind tunnel with cold carbon dioxide.
			* An alternate wind tunnel design would be a torus or hollow donut shaped wind tunnel to be made with the donut hole having a one kilometer radius. It should contain a ring in a track along the wall closest to the center of the donut hole. This ring should be electrically accelerated to 450 meters per second and supported in its track by a film of high-pressure carbon dioxide. Model aircraft can be supported in such a wind tunnel by this ring and experience the effects of supersonic ground effect. The radial acceleration needed to hold the models in circular motion would be 20.7 gravities. The portion of the ring not supporting the models would be weighted to balance loading radially with respect to the center of the donut hole. Gas added to the wind tunnel by the carbon dioxide bearings would be removed by vacuum pumps.
	*Landing at a speed in the neighborhood of 1000 mph (450 meters per second or mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and orientational stability are the problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.		*Landing at a speed in the neighborhood of 1000 mph (450 meters per second or mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and orientational stability are the problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.

	==references==		==references==
	<references/>		<references/>

Farred: /* Mars to Luna Transport */ adding metric speed

2010-08-02T23:03:15Z

Mars to Luna Transport: adding metric speed

← Older revision		Revision as of 00:03, 3 August 2010
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	*This sort of problem is made more difficult by the need to consider the reflection of shock waves in supersonic flight in ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref> http://www.speedace.info/thrust_ssc </ref>		*This sort of problem is made more difficult by the need to consider the reflection of shock waves in supersonic flight in ground effect. Such problems were handled successfully when the "Thrust SSC" broke the speed of sound on land on the 15th of October 1997, setting of the world's land speed record. <ref> http://www.speedace.info/thrust_ssc </ref>
	*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. At least with only 0.1 psi of carbon dioxide needed for a simulation, it would not cost as much as otherwise to fill the wind tunnel with cold carbon dioxide.		*An ordinary wind tunnel by itself is insufficient for testing craft in supersonic ground effect conditions. A moving belt of caterpillar like treads on the bottom of the wind tunnel moving as fast as the gas in the wind tunnel could simulate the runway rushing past during landing. Having a belt of treads that are broad enough and move fast enough for the simulation would be expensive, but not as expensive as doing the testing on Mars. At least with only 0.1 psi of carbon dioxide needed for a simulation, it would not cost as much as otherwise to fill the wind tunnel with cold carbon dioxide.
	*Landing at a speed in the neighborhood of 1000 mph (mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and orientational stability are the problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.		*Landing at a speed in the neighborhood of 1000 mph (450 meters per second or mach 1.9 on Mars) might seem more difficult than the feat accomplished by "Thrust SSC," but moving through only 150th of the gas pressure (100th of the density) more than compensates for the increased speed. Maintaining lift and orientational stability are the problems for which we have aeronautical engineers, computational fluid dynamics, and wind tunnels.

	==references==		==references==
	<references/>		<references/>