Normal Shock Waves topics include: Normal shock equations, flow compressible and its velocity measurement. A normal shock wave is a one-dimensional flow configuration that can be used to study flow behavior and transport processes.  A normal shock wave is a shock with a wave front that is perpendicular to the freestream flow. They occur in supersonic internal and jet flows.  A normal shock wave is the most fundamental type of shock. It is a traveling wave that moves relative to the fluid faster than the local speed of sound.  Here are some characteristics of normal shock waves: Shock... Show more

Normal Shock Waves topics include: Normal shock equations, flow compressible and its velocity measurement.

A normal shock wave is a one-dimensional flow configuration that can be used to study flow behavior and transport processes. 

A normal shock wave is a shock with a wave front that is perpendicular to the freestream flow. They occur in supersonic internal and jet flows. 
A normal shock wave is the most fundamental type of shock. It is a traveling wave that moves relative to the fluid faster than the local speed of sound. 

Here are some characteristics of normal shock waves:
Shock waves are very thin
Shock waves are highly localized irreversibilities in the flow

As fluid passes through a shock wave, pressure, temperature, and density will increase; velocity will decrease:
Within the distance of a mean free path, the flow passes from a supersonic to a subsonic state, the velocity decreases suddenly and the pressure rises sharply 
Shock waves are typically very thin, with thicknesses on the order of 1 µm. 

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Aerodynamics Practice Test: Normal Shock Waves

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25 Questions

1. The isothermal compressibility is given as___________

\(\frac {\rho }{p}\) \(\frac {1}{p}\) Same as isentropic compressibility\(\frac {1}{\gamma p}\)

2. The supersonic flow over a blunt body is given. Mark the area where the normal shock wave exists.

iiiiiiiv

3. For compressible flow also, we can calculate velocity with the Pitot and static pressure found.

Don't KnowMaybeFalseTrue

4. For subsonic compressible flow, which of these is not required to be measured separately to find the velocity of flow?

Stagnation pressureMach numberStatic pressureFree-stream of sound

5. The Rayleigh Pitot tube formula does not relate which of these quantities to the others?

Pitot pressureUpstream flow velocityFree-stream static pressureFree-stream Mach number

6. Mach number is a measure of the directed motion of the gas compared with the random thermal motion of the molecules.

Don't KnowFalseTrueMaybe

7. Select the correct statement for a Mach wave.

\(\frac {\rho_2}{\rho_1}\)=∞M > 1\(\frac {T_2}{T_1}\)=1\(\frac {P_2}{P_1}\)=0.528

8. Incompressible flow is a myth actually.

FalseMaybeDon't knowTrue

9. Specifying the temperature ratio across the normal shock wave will yield which of the following across the normal shock wave?

Upstream flow velocityDownstream temperatureUpstream Mach numberDownstream flow velocity

10. The equation a=-ρ\(\frac {da}{d\rho }\) where a is the speed of sound in the medium is the mathematical expression derived for the sound waves, which are _________

AdiabaticReversibleIsentropicIncompressible

11. For a calorically perfect gas, the ratio of stagnation to static temperature depends upon_______

MR, Mγ , Mγ

12. For a perfect gas, if we half the density, keeping the temperature same the speed of sound changes. This is due to the change in pressure.

MaybeDon't knowFalseTrue

13. The fundamental expression for the speed of sound in a gas is not given by which of the following equations?

a=\(\sqrt {(\frac {\partial p}{\partial \rho })s}\) a=\(\sqrt {\gamma ^2RT}\) a2=\(\frac {dp}{d\rho }\) a=\(\sqrt {\frac {\gamma p}{\rho }}\)

14. Which is not true for continuity equation of normal shock?

Steady flowNo viscosityρ1u1A1=ρ2u2A2ρ1u1=ρ2u2

15. .The properties of a flow with subscript * denotes M=1. Which of these is the correct ratio for a flow with gamma= 1.4?"

\(\frac {P^*}{P_0}\)=0.833\(\frac {\rho ^*}{\rho_0}\)=0.634\(\frac {T^*}{T_0}\)=0.528Data inadequate

16. Select the false statement for the normal shock wave.

The total temperature remains constantNormal shock wave is a compression waveEntropy increases across normal shock waveThe total pressure remains constant

17. For a non-perfect gas, if we double the pressure while keeping the temperature same, the speed of sound remains the same.

MaybeFalseTrueDon't Know

18. A shock wave that is normal to the upstream flow is a rare case.

Don't KnowMaybeFalseTrue

19. The total temperature across the normal shock wave is constant. Which statement gives the wrong reason for this?

Thermal dissipation thereCalorifically perfect gasNormal shock wave has an isentropic flowAdiabatic flow across normal shock wave

20. Prandtl relation can also be expressed in terms of characteristic Mach number as 1=M\(_1^*\)M\(_2^*\).

TrueFalseDon't knowMaybe

21. Shock waves can occur both in subsonic and supersonic medium since the concerning equations are not concerned with whether M > 1 or M < 1.

FalseTrueMaybeDon't Know

22. For a particular gas, Mach number behind the shock wave is a function of which all parameters ahead of the shock wave. Choose the correct option.

Mach number, temperature, pressureMach number, pressureMach number, temperatureMach number only

23. The definition of flow being compressible is______

M > 0.3Depends on precision requiredM > 0.5Another name for supersonic flows

24. The isentropic compressibility, in terms of speed of sound in any medium is given by ________

τs=ρa2τs=\(\frac {1}{\rho a}\) τs=\(\frac {1}{\rho a^2}\) τs=\(\frac {\rho }{a^2}\)

25. Select the incorrect statement out of the following.

Speed of sound in incompressible medium is zeroMach number for finite velocity object, in incompressible flow is zerolimτs→0⁡ is the case of an incompressible flowIncompressible flow is theoretically zero-Mach number flows