6 Wind and Water Tunnel Equipment
433
Fig. 6.61 U.S. x-43 hypersonic vehicle (cruising Mach 7)
value. In the experiment, the shock wave diaphragm is broken first. From the
rupture of the diaphragm, a one-dimensional unsteady flow process occurs
in the shock wave tube. When the diaphragm is broken, the high-pressure
driving gas rushes into the low-pressure chamber, and a contact surface is
formed between the two gases. The driven gas on the right side of the contact
surface is strongly compressed, forming a positive shock wave moving to the
right at supersonic speed. The right side of the right-traveling shock wave is
the undisturbed region, and the left side of the right-traveling shock wave
is the original low-pressure chamber gas swept by the positive shock wave
and moving to the right with a certain velocity. After shock compression, the
pressure and temperature of the gas in the original low-pressure chamber are
increased obviously. At the same time, the expansion wave traveling to the
left propagates through the gas in the original high-pressure chamber. The
stability of the high enthalpy flow in the shock tube is very short, usually
less than 1 ms. The high-performance shock tube can be used to study the
phenomena of gas dissociation and ionization. If the right end of the shock
tube is not closed, but the diaphragm (nozzle diaphragm), nozzle, test section,
and true empty box are installed at the right end of the shock tube, the shock
wind tunnel is formed. Shock wave wind tunnel is a kind of wind tunnel
that uses shock wave to compress gas and then produces superhigh velocity
airflow by steady expansion method. After the shock diaphragm is broken,
the shock wave moves to the right and the driven gas is compressed and
heated. When the positive shock wave reaches the right end and meets the
nozzle diaphragm, the reflected shock wave in the left row is generated, and at
the same time, there is a rupture of the nozzle diaphragm. The test section is
connected with the true empty box. Under the action of a fairly high-pressure
433
Fig. 6.61 U.S. x-43 hypersonic vehicle (cruising Mach 7)
value. In the experiment, the shock wave diaphragm is broken first. From the
rupture of the diaphragm, a one-dimensional unsteady flow process occurs
in the shock wave tube. When the diaphragm is broken, the high-pressure
driving gas rushes into the low-pressure chamber, and a contact surface is
formed between the two gases. The driven gas on the right side of the contact
surface is strongly compressed, forming a positive shock wave moving to the
right at supersonic speed. The right side of the right-traveling shock wave is
the undisturbed region, and the left side of the right-traveling shock wave
is the original low-pressure chamber gas swept by the positive shock wave
and moving to the right with a certain velocity. After shock compression, the
pressure and temperature of the gas in the original low-pressure chamber are
increased obviously. At the same time, the expansion wave traveling to the
left propagates through the gas in the original high-pressure chamber. The
stability of the high enthalpy flow in the shock tube is very short, usually
less than 1 ms. The high-performance shock tube can be used to study the
phenomena of gas dissociation and ionization. If the right end of the shock
tube is not closed, but the diaphragm (nozzle diaphragm), nozzle, test section,
and true empty box are installed at the right end of the shock tube, the shock
wind tunnel is formed. Shock wave wind tunnel is a kind of wind tunnel
that uses shock wave to compress gas and then produces superhigh velocity
airflow by steady expansion method. After the shock diaphragm is broken,
the shock wave moves to the right and the driven gas is compressed and
heated. When the positive shock wave reaches the right end and meets the
nozzle diaphragm, the reflected shock wave in the left row is generated, and at
the same time, there is a rupture of the nozzle diaphragm. The test section is
connected with the true empty box. Under the action of a fairly high-pressure