What happens to the total pressure (P0) of a gas as it passes through a normal shock?
Explanation
A key characteristic of a normal shock is the loss of total pressure. While total temperature is conserved (in an adiabatic shock), the process is highly irreversible, leading to an increase in entropy and a corresponding decrease in the total pressure (P0). This represents a loss in the flow's ability to perform work isentropically.
Other questions
What are the four primary equations used to describe the conditions across a normal shock for a perfect gas?
What fundamental principle dictates that a normal shock wave can only proceed from a supersonic flow (Mx > 1) to a subsonic flow (My < 1)?
How does the total temperature (T0) of a perfect gas change across a stationary normal shock?
According to the Rankine-Hugoniot relation for a normal shock, what is the downstream Mach number (My) squared, as a function of the upstream Mach number (Mx) squared and the specific heat ratio (k)?
For a normal shock in a perfect gas with k=1.4, if the upstream Mach number (Mx) is 3.0, what is the approximate ratio of downstream pressure to upstream pressure (Py/Px)?
What is Prandtl's condition for a normal shock, relating the upstream velocity (U1), downstream velocity (U2), and the critical speed of sound (c*)?
As the upstream Mach number (Mx) of a normal shock becomes very large (approaches infinity), what is the limiting value of the downstream Mach number (My)?
How is the analysis of a moving shock wave, such as one created by a suddenly closed valve, typically simplified?
In the analysis of a moving shock created by a valve suddenly stopping a flow, what is the 'upstream' Mach number in the moving coordinate system (Mx') if the original flow Mach number was Mx and the shock Mach number is Msx?
The strength of a weak normal shock is defined by the dimensionless pressure rise, P-hat = (Py - Px) / Px. How is P-hat related to the upstream Mach number (Mx) for small perturbations?
A gas flowing at a Mach number of 0.4 is brought to a partial stop by closing a valve, such that the Mach number behind the shock is 0.2. What type of problem does this scenario represent?
In a shock tube, what are the conditions in zone 2, the region immediately behind the moving shock front?
What is the relationship between the density ratio (rho_y/rho_x) and the velocity ratio (Ux/Uy) across a normal shock?
In a reflective shock from a suddenly closed valve, a gas flow at a prime Mach number Mx' of 1.2961 is brought to a complete stop (My' = 0). For k=1.4, what is the resulting pressure ratio (Py/Px) of the shock?
Why are two solutions (intersections) obtained when plotting Fanno flow and Rayleigh flow curves on a T-s diagram?
What is the relationship for the density ratio (rho_y/rho_x) across a normal shock as a function of the upstream Mach number (Mx) and specific heat ratio (k)?
When a piston moves into a still gas, it creates a moving shock. The analysis involves a 'strange' Mach number, Myx', which is defined as what?
What is the primary reason for the total pressure loss across a normal shock?
In the analysis of a moving shock in a stationary medium (suddenly open valve), the stagnation temperature in stationary coordinates rises. Why does this occur?
For a shock moving at 450 m/sec into stagnant air at 300 K (k=1.3, R=287 J/kgK), the calculated prime Mach number My' is approximately 1.296. What is the corresponding stationary upstream Mach number (Mx) for this shock?
What is the relationship between the temperature ratio (Ty/Tx) and the pressure ratio (Py/Px) across a normal shock?
In the shock tube diagram (Figure 5.16), what separates zone 2 (shocked gas) from zone 3 (expanded driver gas)?
A shock is moving into a stationary medium. If the specific heat ratio is k=1.4, what is the theoretical maximum possible Mach number of the gas behind the shock (My') in the stationary frame?
For a gas with k=1.4, what is the minimum upstream Mach number (Mx) required to create a normal shock?
What physical assumption allows the thickness of a normal shock to be considered very small or negligible in the governing equations?
In the analysis of a moving shock into stationary medium from a suddenly opened valve, how is the shock Mach number ahead of the shock (Msx) defined?
For a normal shock with an upstream Mach number of 2.0 and k=1.4, what is the total pressure ratio P0y/P0x?
What is assumed about chemical reactions, such as condensation, within the very narrow width of a normal shock in the simplified model?
What does the star Mach number, M*, represent?
A gas is flowing in a pipe with a Mach number of 0.4. A valve is closed such that the Mach number is reduced by half to 0.2. What is the approximate stationary Mach number (Mx) of the shock wave generated, assuming k=1.4?
In the momentum equation for a normal shock, Px - Py = rho_y * Uy^2 - rho_x * Ux^2, what physical principle does this equation represent?
For a shock moving into still air (Mx'=0), how is the downstream Mach number in the moving frame (My') related to the shock Mach number (Msy)?
What is the primary characteristic of the 'contact surface' in a shock tube?
If a piston accelerates very rapidly in a tube of air at 300 C with M=0.4, and the air next to the piston reaches M=0.8, what is the approximate speed of the shock wave created? The speed of sound in the undisturbed air is 347.2 m/s and k=1.4.
What does the dimensionless group M*1 * M*2 equal, according to Prandtl's condition?
In the industrial problem presented in Example 5.10, a valve is opened between a 30 Bar reservoir and a pipe leading to a 1 Bar ambient condition. What phenomenon limits the initial flow characteristics?
If a normal shock occurs with an upstream Mach number of 4.0 in a gas with k=1.4, what is the approximate downstream Mach number (My)?
What is the primary difference in the stagnation temperature change between a stationary shock and a moving shock (viewed from a stationary frame)?
In order to double the temperature across a reflective shock from a suddenly closed valve (Ty/Tx = 2.0), what must be the stationary Mach number (Mx) of the shock, assuming k=1.4?
What does a value of P0y/P0x = 1.0 signify for a flow process?
If two pistons in a 1-meter long tube move toward each other, one creating a shock with Us=1.0715*c and the other Us=1.1283*c, where c=347 m/s, approximately how long will it take for the shocks to collide?
Which statement accurately describes the change in static properties across a normal shock?
What is the key simplification that allows the Fanno flow and Rayleigh flow models to be used in analyzing a normal shock?
For a shock moving into a stationary medium with k=1.3, what is the maximum possible Mach number of the gas behind the shock (My')?
According to Figure 5.3, how does the total pressure ratio (P0y/P0x) change as the upstream Mach number (Mx) increases from 1 to 10?
If a shock has a static pressure ratio (Py/Px) of 6.317 and a temperature ratio (Ty/Tx) of 2.0, what was the approximate upstream prime Mach number (Mx') of the flow before it was stopped by a valve, for a gas with k=1.4?
The relationship My^2 = (Mx^2 + 2/(k-1)) / ( (2k/(k-1))Mx^2 - 1 ) is described as a 'symmetrical equation'. What does this symmetry imply?
In the general case of a moving shock where a gas flows into another gas with a different velocity (partially open valve), what additional parameter must be supplied to solve the problem, compared to a shock in a stationary medium?
What is the physical interpretation of the 'shock-choking' phenomenon?