VM-EXD-MECH-015

VM-EXD-MECH-015
Regular and Mach Deflections Off of a 2-D Wedge

Overview

Reference: Harlow, Francis H. et al., Fluid Dynamics – A LASL Monograph, LA-4700, June 1971.
Analysis Type(s): Explicit Dynamics 2-D
Elements:

Multi-material Euler Quad

Euler Ideal Gas Quad

Boundary Conditions: Euler Inflow, Euler Outflow
Structural Interactions: No
Fluid-Structure Interactions: Yes
Bonds: No
Materials: Ideal Gas

Test Case

Run a dynamic flow analysis of a Mach 2 shock reflection off a 25-degree wedge, which should produce a Mach reflection.

Because the appearance of the configuration is independent of magnification, there is no significant length to the system.

Material PropertiesGeometric Properties
Initial Conditions

Heat capacity ratio,
Density of gas, g/mL
Pressure of gas, MPa
Internal energy, J/kg

Mach 2.0 Flow

Velocity of gas, m/s
Pressure of gas, MPa
Density of gas, g/mL
Internal energy, J/kg
Mach 2.0 Flow

Angle of wedge = 25 °

Calculation Description

Two interacting Euler parts are created. One part is assigned a material with Euler inflow properties and the other Ideal Gas properties. A 25-degree Lagrange wedge is then created to intersect the Euler parts:

Figure 252: 25-Degree Wedge

25-Degree Wedge

Results Comparison

Results shown are from the end of the simulation (t = 0.85 ms):

Figure 253: Mach Reflections Off 25-Degree Wedge

Mach Reflections Off 25-Degree Wedge