VMFL051

VMFL051
Isentropic Expansion of Supersonic Flow Over a Convex Corner

Overview

Reference

John Anderson. Modern Compressible Flow: With Historical Perspective. McGraw-Hill Science/Engineering/Math, 2002

SolverAnsys Fluent, Ansys CFX
Physics/Models

Compressible, inviscid flow

Input File
VMFL051_FLUENT.cas for Ansys Fluent
VMFL051_CFX.def for Ansys CFX
Project FilesLink to Project Files Download Page

Test Case

Centered expansion of inviscid supersonic flow around a corner is modeled. The expansion results in a change in direction of the flow, a drop in static pressure, and increase in Mach number. The approaching flow is supersonic, with a Mach number of 2.5. The expansion process is reversible and adiabatic.

Figure 127: Flow Domain

Flow Domain

Material PropertiesGeometry Boundary Conditions

Density: Ideal Gas law

Specific Heat = 1006.43 J/kg-K

Molecular weight = 28.966

Angle round the corner = 195°

Inlet:

Pressure = 202636.9 Pa
Mach number = 2.5
Static temperature = 300 K (In CFX, the corresponding velocity is specified).

Wall is adiabatic.

Analysis Assumptions and Modeling Notes

The flow is steady, inviscid, and incompressible. Analytic expressions for isentropic expansion can be used to calculate the Mach number downstream of the corner.

Results Comparison for Ansys Fluent

Table 33: Comparison of Mach Number Downstream of the Corner, after Expansion

 TargetAnsys FluentRatio
Mach number after expansion3.23703.23160.9980

Results Comparison for Ansys CFX

Table 34: Comparison of Mach Number Downstream of the Corner, after Expansion

 TargetAnsys FluentRatio
Mach number after expansion3.2373.23540.9995