Podcast
Questions and Answers
What is the primary factor that causes an oblique shock at angle β?
What is the primary factor that causes an oblique shock at angle β?
- The presence of an obstruction in the flow path
- The initial Mach number of the flow
- The deflection angle θ caused by an object (correct)
- The nature of the gas used in the flow
Which statement best describes the relationship between Mach number M1 and shock angles β?
Which statement best describes the relationship between Mach number M1 and shock angles β?
- Higher Mach numbers only produce weak shocks.
- A lower shock angle β results in a detached shock.
- There is always one unique shock angle for a given Mach number.
- Two possible shock angles exist for a given deflection angle. (correct)
What happens if the deflection angle θ exceeds the maximum deflection angle θmax?
What happens if the deflection angle θ exceeds the maximum deflection angle θmax?
- The Mach number decreases significantly.
- A detached normal shock forms. (correct)
- The flow remains unchanged.
- A weak shock is generated.
In the context of air (k=1.4) when M1 = 3, what is the approximate value of the maximum deflection angle θmax?
In the context of air (k=1.4) when M1 = 3, what is the approximate value of the maximum deflection angle θmax?
As the deflection θ approaches zero, what occurs to the weak shock?
As the deflection θ approaches zero, what occurs to the weak shock?
What happens to the oblique shock angle as the Mach number increases?
What happens to the oblique shock angle as the Mach number increases?
At what Mach number does the normal shock first attach and become oblique for an angle of 10°?
At what Mach number does the normal shock first attach and become oblique for an angle of 10°?
What is the speed of sound (C1) at 4°C in the given scenario?
What is the speed of sound (C1) at 4°C in the given scenario?
For the upper surface of the airfoil with an angle of attack of 1°, what is the deflection angle θu?
For the upper surface of the airfoil with an angle of attack of 1°, what is the deflection angle θu?
What is the upstream Mach number (M1) calculated for the airfoil traveling at 600 m/s?
What is the upstream Mach number (M1) calculated for the airfoil traveling at 600 m/s?
What method can be used to solve for βu in the context provided?
What method can be used to solve for βu in the context provided?
What does a normal Mach number close to one indicate about the oblique shock strength?
What does a normal Mach number close to one indicate about the oblique shock strength?
What is the angle of the leading edge (δ) of the airfoil in the example given?
What is the angle of the leading edge (δ) of the airfoil in the example given?
What is the relationship of the deflection angle θ to the incoming Mach number M1 and the oblique shock angle β as expressed in Equation 13.49?
What is the relationship of the deflection angle θ to the incoming Mach number M1 and the oblique shock angle β as expressed in Equation 13.49?
Which statement accurately describes the characteristics of an oblique shock compared to a normal shock?
Which statement accurately describes the characteristics of an oblique shock compared to a normal shock?
What does the angle θ represent in the context of oblique shocks?
What does the angle θ represent in the context of oblique shocks?
In which scenario can M2 be supersonic?
In which scenario can M2 be supersonic?
What is the significance of the Excel workbook mentioned in relation to oblique shocks?
What is the significance of the Excel workbook mentioned in relation to oblique shocks?
Which equation demonstrates the relationship between the normal velocity ratios for oblique shocks?
Which equation demonstrates the relationship between the normal velocity ratios for oblique shocks?
What is the effect of increasing the shock angle β on the deflection angle θ for a given Mach number M1?
What is the effect of increasing the shock angle β on the deflection angle θ for a given Mach number M1?
How does the normal shock function relate to the solution of oblique shock problems?
How does the normal shock function relate to the solution of oblique shock problems?
What is the speed of sound calculated for the air at -2°C?
What is the speed of sound calculated for the air at -2°C?
After experiencing a normal shock, what is the value of downstream pressure $P_2$?
After experiencing a normal shock, what is the value of downstream pressure $P_2$?
What is the upstream Mach number $M_1$ before the normal shock?
What is the upstream Mach number $M_1$ before the normal shock?
For an oblique shock at angle β = 30°, what is the downstream temperature $T_2$ after the shock?
For an oblique shock at angle β = 30°, what is the downstream temperature $T_2$ after the shock?
What is the ratio of the downstream pressure $P_2$ to upstream pressure $P_1$ after an oblique shock?
What is the ratio of the downstream pressure $P_2$ to upstream pressure $P_1$ after an oblique shock?
What is the downstream velocity $V_2$ after the oblique shock calculated from the velocity components?
What is the downstream velocity $V_2$ after the oblique shock calculated from the velocity components?
What happens to the air's Mach number after it experiences a normal shock?
What happens to the air's Mach number after it experiences a normal shock?
What is the tangential component of velocity $V_{1, cos β}$ for the oblique shock?
What is the tangential component of velocity $V_{1, cos β}$ for the oblique shock?
What is the deflection angle θ for the air experiencing an oblique shock?
What is the deflection angle θ for the air experiencing an oblique shock?
What changes need to be made in the shock equations when analyzing oblique shocks compared to normal shocks?
What changes need to be made in the shock equations when analyzing oblique shocks compared to normal shocks?
Given the normal velocity components $V_1$ and $V_2$, what is the formula for $V_1$?
Given the normal velocity components $V_1$ and $V_2$, what is the formula for $V_1$?
What is the final value of downstream Mach number $M_2$ after the oblique shock?
What is the final value of downstream Mach number $M_2$ after the oblique shock?
What is represented by the equation $M_2^2 = M_1^2 + \frac{2}{k-1} (1 - M_1^2)$?
What is represented by the equation $M_2^2 = M_1^2 + \frac{2}{k-1} (1 - M_1^2)$?
Which parameter is NOT part of the equations governing oblique shocks for an ideal gas?
Which parameter is NOT part of the equations governing oblique shocks for an ideal gas?
Which equation denotes the relationship between total pressures before and after an oblique shock?
Which equation denotes the relationship between total pressures before and after an oblique shock?
What is the equivalent normal shock problem used for analyzing oblique shocks?
What is the equivalent normal shock problem used for analyzing oblique shocks?
In the context of oblique shocks, what is needed to obtain ratios like $T_2/T_1$?
In the context of oblique shocks, what is needed to obtain ratios like $T_2/T_1$?
Which specific heat ratio is commonly used for air in relation to oblique shock calculations?
Which specific heat ratio is commonly used for air in relation to oblique shock calculations?
Study Notes
Oblique Shocks
-
Oblique shocks are similar to normal shocks, but the flow is deflected by an angle.
-
The equations for oblique shocks are the same as for normal shocks, but we replace the velocity with the normal velocity component.
-
The normal velocity component is the velocity component perpendicular to the shock wave.
-
We can use the same normal shock equations with the normal velocities for oblique shocks.
-
The oblique shock equations for an ideal gas with constant specific heats are obtained directly from the normal shock equations.
-
The normal shock flow functions can be used to analyze oblique shock problems.
-
Oblique shocks are always weaker than normal shocks for a given supersonic flow.
-
Oblique shocks can be analyzed as an equivalent normal shock problem.
-
The deflection angle of an oblique shock is the angle between the upstream flow direction and the downstream flow direction.
-
The maximum deflection angle for a given Mach number is limited.
-
There are generally two possible shock angles for a given Mach number and deflection angle: a weak shock and a strong shock.
-
For zero deflection, the weak shock becomes a Mach wave.
Normal shock vs Oblique shock comparison
-
The pressure, temperature, and speed after a normal shock are different from those after an oblique shock.
-
A normal shock is stronger than an oblique shock.
-
The downstream Mach number can be subsonic or supersonic after an oblique shock, but it is always subsonic after a normal shock.
Example 13.11
- Air flows at a certain speed and temperature.
- The air experiences a normal shock.
- The flow is then compared to that after an oblique shock.
- The downstream pressure, temperature, and speed are calculated for both cases.
Example 13.12
- An airplane travels at a certain speed.
- The airfoil has a sharp leading edge.
- The pressures on the upper and lower surfaces of the airfoil are calculated.
- The deflection angle for both the upper and lower surfaces are computed.
- The oblique shock angle is computed using various methods.
- The pressure ratios for both the upper and lower surfaces are computed, implying the oblique shock is weak.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz explores the concept of oblique shocks, focusing on their similarities and differences with normal shocks. Test your understanding of how oblique shocks affect supersonic flow and the use of normal shock equations for analysis. Ideal for students studying fluid dynamics or aerodynamics.
