Q7 - Oblique Shock Flashcards
Derive general relations for an oblique shock from conservation laws
Mass: DI of rhovn dA = 0. rho1v1n = rho2 v2n
Momentum:DI of vrhovn dA + DI of Pn*dA = 0
Normal: DI of rhovn^2dA + DI of PdA = 0
P1 +rho1v1n^2 = P2 +rho2*v2n^2 =
Tangential: DI of rhovtvn*dA = 0. v1t = v2t
Energy: DI of h0rhovn*dA = 0.
h0 = const
h1 + ((v1n^2)/2) = h2 + ((v2n^2)/2)
A supersonic flow is deflected on a wall corner by the angle of 18 Degrees toward the flow as shown in the picture below. Using the diagram, determine the Mach number range over
which the oblique shock is attached.
Use Beta - Theta diagram to find highest Mach number possible with that theta to make sure the shock is attached. Therefore find corresponding Mach number that has
Theta_max < Theta
A supersonic flow with the Mach number of 2 is deflected by the angle of 18 Degrees toward the
flow as shown in the picture above.
(c) Using the diagram, find all possible angles of oblique shock wave.
Use theta Beta diagram to find corresponding beta diagram for given theta and Mach number, also find the possible theta max and beta max.
A supersonic flow with the Mach number of 2 is deflected by the angle of 18 Degrees toward the
flow as shown in the picture above.
(d) Find the Mach number of the flow after the shock.
Find M1n = M1sin(beta) and M1t = M1cos(beta). Use equation from data Sheet to find either M2 or M2n, but final goal is to find M2.
A supersonic flow with the Mach number of 2 is deflected by the angle of 18 Degrees toward the
flow as shown in the picture above.
(e) Find the ratio of pressures before and after the shock.
A supersonic flow with the Mach number of 2 is deflected by the angle of 18 Degrees toward the
flow as shown in the picture above.
(f) Find the ratio of stagnation pressures before and after the shock.
A supersonic flow with the Mach number of 2 is deflected by the angle of 18 Degrees toward the
flow as shown in the picture above.
(g) Find the change in the specific entropy across the shock.
