info
Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Download Hypersonic 1 Vst !!BETTER!!
6 views
Skip to first unread message
Heidi Asman
Jan 26, 2024, 5:31:13 AMJan 26
to
The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since individual physical changes in the airflow (like molecular dissociation and ionization) occur at different speeds; these effects collectively become important around Mach 5-10. The hypersonic regime can also be alternatively defined as speeds where specific heat capacity changes with the temperature of the flow as kinetic energy of the moving object is converted into heat.[2]
While the definition of hypersonic flow can be quite vague and is generally debatable (especially due to the absence of discontinuity between supersonic and hypersonic flows), a hypersonic flow may be characterized by certain physical phenomena that can no longer be analytically discounted as in supersonic flow.[citation needed] The peculiarities in hypersonic flows are as follows:[citation needed]
download hypersonic 1 vst
Download https://xiuty.com/2xwbEm
A portion of the large kinetic energy associated with flow at high Mach numbers transforms into internal energy in the fluid due to viscous effects. The increase in internal energy is realized as an increase in temperature. Since the pressure gradient normal to the flow within a boundary layer is approximately zero for low to moderate hypersonic Mach numbers, the increase of temperature through the boundary layer coincides with a decrease in density. This causes the bottom of the boundary layer to expand, so that the boundary layer over the body grows thicker and can often merge with the shock wave near the body leading edge.[citation needed]
The "supersonic regime" usually refers to the set of Mach numbers for which linearised theory may be used; for example, where the (air) flow is not chemically reacting and where heat transfer between air and vehicle may be reasonably neglected in calculations. Generally, NASA defines "high" hypersonic as any Mach number from 10 to 25, and re-entry speeds as anything greater than Mach 25. Among the spacecraft operating in these regimes are returning Soyuz and Dragon space capsules; the previously-operated Space Shuttle; various reusable spacecraft in development such as SpaceX Starship and Rocket Lab Electron; as well as (theoretical) spaceplanes.[citation needed]
Hypersonic flows, however, require other similarity parameters. First, the analytic equations for the oblique shock angle become nearly independent of Mach number at high (>10) Mach numbers. Second, the formation of strong shocks around aerodynamic bodies means that the freestream Reynolds number is less useful as an estimate of the behavior of the boundary layer over a body (although it is still important). Finally, the increased temperature of hypersonic flow mean that real gas effects become important. Research in hypersonics is therefore often called aerothermodynamics, rather than aerodynamics.[3]
For aircraft speeds which are much greater than the speed of sound,the aircraft is said to be hypersonic.Typical speeds for hypersonic aircraft are greater than 3000 mphand Mach number M greater than five, M > 5.We are going to define ahigh hypersonicregime at M > 10 to account for re-entry aerodynamics.The chief characteristic of hypersonic aerodynamics is that thetemperatureof the flow is so great that the chemistry of the diatomic molecules of theairmust be considered. At low hypersonic speeds, the molecular bondsvibrate, which changes the magnitude of the forces generated bythe air on the aircraft. At high hypersonic speeds, the moleculesbreak apart producing an electrically charged plasma around theaircraft. Large variations inair densityandpressureoccur because ofshock waves, andexpansions.
The only manned aircraft to fly in the low hypersonic regime were theX-15 and the Space Shuttle during re-entry. The X-15 is shown on the figure.The X-15 used arocketpropulsion system to achieve sustained Mach 6 flight.Recently, an un-manned X-43A used ascramjet,or supersonic combustionramjet,to make two hypersonic flights; one at Mach 7, the other at Mach 10.Because of the pressure losses associated with theterminal shockof theinlet,a ramjet has very limited performance beyond Mach 5.Becauseliftanddragdepend on the square of thevelocity,hypersonic aircraft do not require a largewing area.For Mach numbers greater than 5, the frictional heating ofthe airframe by the air becomes so high thatvery special nickel alloys are required for thestructure. For some proposed hypersonic aircraft,the skin is actively cooled by circulating fuel throughthe skin to absorb the heat.
CBO analyzes the hypersonic missiles being developed by the U.S. military and compares them with less expensive existing or potential weapons that might fill similar roles, such as cruise missiles or ballistic missiles.
In this report, the Congressional Budget Office analyzes the hypersonic weapons being developed by the U.S. military and compares them with less expensive existing or potential weapons that might fill similar roles, such as ballistic missiles or cruise missiles. CBO reached the following conclusions:
The Mach 8 quiet wind tunnel and the HYPULSE tunnel offer controlled environments to research several facets of high-speed flight. The new Mach 8 quiet wind tunnel more closely simulates flight and provides more accurate data than conventional hypersonic wind tunnels.
The HYPULSE tunnel uses a shock wave of high-temperature air to recreate specific hypersonic flight conditions. It will allow flight simulations at speeds ranging from Mach 5 to as high as Mach 40. Purdue will be only the second university in the U.S. to offer HYPULSE test capabilities. The university currently offers one of only two working Mach 6 quiet tunnels in the country.
This potential increase in funding would build on previous investments by federal agencies and industry to help better integrate hypersonic systems with the U.S national security strategy. The new HYPULSE tunnel is a donation from Northrop Grumman Corp. In 2019, Purdue received a contract from the Air Force Research Laboratory to support the development of the first quiet Mach 8 tunnel in the world, the first facility of its kind capable of collecting data at speeds greater than Mach 6. Collecting data at higher Mach numbers is critical to extending the understanding of flow physics, especially heat transfer and flight control effectiveness, as Department of Defense programs continue working to fly faster and farther.
In addition to the HYPULSE and the quiet wind tunnel, the building also will feature advanced facilities that will enable the study of high-temperature materials applications. Hypersonic flight can create air friction above 1,000 degrees Celsius, requiring unique processes and materials to withstand such conditions. The research facility offers the chance to design and test these new materials. It also will create space for Purdue researchers to further capabilities to design, build and test hypersonic systems.
Several U.S. Officials say Russia and China are ahead of the U.S. in hypersonic missile technology. Now, Texas A&M and the Bush Combat Development Complex plan to position the United States to become number one.
A recent example of the effect of aerodynamic heating on a hypersonic vehicle is the test of the Hypersonic Technology Vehicle 2 (HTV-2), very recently announced by the Defense Advanced Research Projects Agency (DARPA). In August 2011, this unmanned vehicle was powered by rockets to Mach 20, after which it spent about 200 seconds flying within the atmosphere before the intense aerodynamic heating resulted in the skin peeling away from the internal structure. The flight was finally aborted and was sent plunging into the Pacific Ocean.
Are these weapons and their employment simply an evolution of existing missiles? Or a revolution that threatens to upset the balance of power? The answer still depends on decisions yet to be made. Russia appears closest to fielding hypersonic missiles, as it aspires to deploy the Avangard glide vehicle before the year is out. The United States has ambitious goals for accuracy and precision, but its most viable programs are not expected to reach operational capability until 2022. Meanwhile, China has been characteristically vague on their hypersonic weapons while still letting it be known that they are firmly committed to their development.
A trio of questions needs to be considered: What audience can hypersonic weapons be leveraged against, what tactical utility do they provide, and what strategic objectives can be advanced by using them or threatening to use them? Framing the discussion in this way is useful for delving deeper into why nations are pursuing hypersonic weapons as well as making initial assessments on how they may be operationalized. The propositions below are not exhaustive; they are meant to provoke discussion. They pair a particular application with a particular country, but there is nothing stopping Russia, China, or the United States from taking advantage of any application discussed below.
If launched concurrently, a Chinese YJ-83 cruise missile traveling 0.9 Mach would hit its target 100 miles away at the same time a DF-17 hypersonic glide vehicle going Mach 15 hit its target at 1,500 miles. That flight time is just under nine minutes. This means that Chinese forces can position their launchers to impose near-instantaneous strikes anywhere within the first island chain that stretches from Japan through the South China Sea before hooking into Vietnam, as well as much of the second island chain reaching out toward Guam and the Marianas. Weapons launched from Chinese warships and shore batteries could be synchronized to simultaneously cripple U.S. naval assets in the South China Sea, air and amphibious forces on Okinawa, and 7th Fleet Headquarters in Sasebo. While the threat of hypersonic weapons to high value targets like aircraft carriers is concerning, the deeper problem is an improved Chinese ability to hit those high value targets as well as other units simultaneously and with very little warning.
f5d0e4f075
While the definition of hypersonic flow can be quite vague and is generally debatable (especially due to the absence of discontinuity between supersonic and hypersonic flows), a hypersonic flow may be characterized by certain physical phenomena that can no longer be analytically discounted as in supersonic flow.[citation needed] The peculiarities in hypersonic flows are as follows:[citation needed]
download hypersonic 1 vst
Download https://xiuty.com/2xwbEm
A portion of the large kinetic energy associated with flow at high Mach numbers transforms into internal energy in the fluid due to viscous effects. The increase in internal energy is realized as an increase in temperature. Since the pressure gradient normal to the flow within a boundary layer is approximately zero for low to moderate hypersonic Mach numbers, the increase of temperature through the boundary layer coincides with a decrease in density. This causes the bottom of the boundary layer to expand, so that the boundary layer over the body grows thicker and can often merge with the shock wave near the body leading edge.[citation needed]
The "supersonic regime" usually refers to the set of Mach numbers for which linearised theory may be used; for example, where the (air) flow is not chemically reacting and where heat transfer between air and vehicle may be reasonably neglected in calculations. Generally, NASA defines "high" hypersonic as any Mach number from 10 to 25, and re-entry speeds as anything greater than Mach 25. Among the spacecraft operating in these regimes are returning Soyuz and Dragon space capsules; the previously-operated Space Shuttle; various reusable spacecraft in development such as SpaceX Starship and Rocket Lab Electron; as well as (theoretical) spaceplanes.[citation needed]
Hypersonic flows, however, require other similarity parameters. First, the analytic equations for the oblique shock angle become nearly independent of Mach number at high (>10) Mach numbers. Second, the formation of strong shocks around aerodynamic bodies means that the freestream Reynolds number is less useful as an estimate of the behavior of the boundary layer over a body (although it is still important). Finally, the increased temperature of hypersonic flow mean that real gas effects become important. Research in hypersonics is therefore often called aerothermodynamics, rather than aerodynamics.[3]
For aircraft speeds which are much greater than the speed of sound,the aircraft is said to be hypersonic.Typical speeds for hypersonic aircraft are greater than 3000 mphand Mach number M greater than five, M > 5.We are going to define ahigh hypersonicregime at M > 10 to account for re-entry aerodynamics.The chief characteristic of hypersonic aerodynamics is that thetemperatureof the flow is so great that the chemistry of the diatomic molecules of theairmust be considered. At low hypersonic speeds, the molecular bondsvibrate, which changes the magnitude of the forces generated bythe air on the aircraft. At high hypersonic speeds, the moleculesbreak apart producing an electrically charged plasma around theaircraft. Large variations inair densityandpressureoccur because ofshock waves, andexpansions.
The only manned aircraft to fly in the low hypersonic regime were theX-15 and the Space Shuttle during re-entry. The X-15 is shown on the figure.The X-15 used arocketpropulsion system to achieve sustained Mach 6 flight.Recently, an un-manned X-43A used ascramjet,or supersonic combustionramjet,to make two hypersonic flights; one at Mach 7, the other at Mach 10.Because of the pressure losses associated with theterminal shockof theinlet,a ramjet has very limited performance beyond Mach 5.Becauseliftanddragdepend on the square of thevelocity,hypersonic aircraft do not require a largewing area.For Mach numbers greater than 5, the frictional heating ofthe airframe by the air becomes so high thatvery special nickel alloys are required for thestructure. For some proposed hypersonic aircraft,the skin is actively cooled by circulating fuel throughthe skin to absorb the heat.
CBO analyzes the hypersonic missiles being developed by the U.S. military and compares them with less expensive existing or potential weapons that might fill similar roles, such as cruise missiles or ballistic missiles.
In this report, the Congressional Budget Office analyzes the hypersonic weapons being developed by the U.S. military and compares them with less expensive existing or potential weapons that might fill similar roles, such as ballistic missiles or cruise missiles. CBO reached the following conclusions:
The Mach 8 quiet wind tunnel and the HYPULSE tunnel offer controlled environments to research several facets of high-speed flight. The new Mach 8 quiet wind tunnel more closely simulates flight and provides more accurate data than conventional hypersonic wind tunnels.
The HYPULSE tunnel uses a shock wave of high-temperature air to recreate specific hypersonic flight conditions. It will allow flight simulations at speeds ranging from Mach 5 to as high as Mach 40. Purdue will be only the second university in the U.S. to offer HYPULSE test capabilities. The university currently offers one of only two working Mach 6 quiet tunnels in the country.
This potential increase in funding would build on previous investments by federal agencies and industry to help better integrate hypersonic systems with the U.S national security strategy. The new HYPULSE tunnel is a donation from Northrop Grumman Corp. In 2019, Purdue received a contract from the Air Force Research Laboratory to support the development of the first quiet Mach 8 tunnel in the world, the first facility of its kind capable of collecting data at speeds greater than Mach 6. Collecting data at higher Mach numbers is critical to extending the understanding of flow physics, especially heat transfer and flight control effectiveness, as Department of Defense programs continue working to fly faster and farther.
In addition to the HYPULSE and the quiet wind tunnel, the building also will feature advanced facilities that will enable the study of high-temperature materials applications. Hypersonic flight can create air friction above 1,000 degrees Celsius, requiring unique processes and materials to withstand such conditions. The research facility offers the chance to design and test these new materials. It also will create space for Purdue researchers to further capabilities to design, build and test hypersonic systems.
Several U.S. Officials say Russia and China are ahead of the U.S. in hypersonic missile technology. Now, Texas A&M and the Bush Combat Development Complex plan to position the United States to become number one.
A recent example of the effect of aerodynamic heating on a hypersonic vehicle is the test of the Hypersonic Technology Vehicle 2 (HTV-2), very recently announced by the Defense Advanced Research Projects Agency (DARPA). In August 2011, this unmanned vehicle was powered by rockets to Mach 20, after which it spent about 200 seconds flying within the atmosphere before the intense aerodynamic heating resulted in the skin peeling away from the internal structure. The flight was finally aborted and was sent plunging into the Pacific Ocean.
Are these weapons and their employment simply an evolution of existing missiles? Or a revolution that threatens to upset the balance of power? The answer still depends on decisions yet to be made. Russia appears closest to fielding hypersonic missiles, as it aspires to deploy the Avangard glide vehicle before the year is out. The United States has ambitious goals for accuracy and precision, but its most viable programs are not expected to reach operational capability until 2022. Meanwhile, China has been characteristically vague on their hypersonic weapons while still letting it be known that they are firmly committed to their development.
A trio of questions needs to be considered: What audience can hypersonic weapons be leveraged against, what tactical utility do they provide, and what strategic objectives can be advanced by using them or threatening to use them? Framing the discussion in this way is useful for delving deeper into why nations are pursuing hypersonic weapons as well as making initial assessments on how they may be operationalized. The propositions below are not exhaustive; they are meant to provoke discussion. They pair a particular application with a particular country, but there is nothing stopping Russia, China, or the United States from taking advantage of any application discussed below.
If launched concurrently, a Chinese YJ-83 cruise missile traveling 0.9 Mach would hit its target 100 miles away at the same time a DF-17 hypersonic glide vehicle going Mach 15 hit its target at 1,500 miles. That flight time is just under nine minutes. This means that Chinese forces can position their launchers to impose near-instantaneous strikes anywhere within the first island chain that stretches from Japan through the South China Sea before hooking into Vietnam, as well as much of the second island chain reaching out toward Guam and the Marianas. Weapons launched from Chinese warships and shore batteries could be synchronized to simultaneously cripple U.S. naval assets in the South China Sea, air and amphibious forces on Okinawa, and 7th Fleet Headquarters in Sasebo. While the threat of hypersonic weapons to high value targets like aircraft carriers is concerning, the deeper problem is an improved Chinese ability to hit those high value targets as well as other units simultaneously and with very little warning.
f5d0e4f075
0 new messages