Accession Number:

ADA247937

Title:

Numerical Simulation of Transient Hypervelocity Flow in an Expansion Tube

Descriptive Note:

Interim rept.

Corporate Author:

INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA

Personal Author(s):

• Jacobs, P. A.

Report Date:

1992-01-01

Pagination or Media Count:

58.0

Abstract:

We present several numerical simulations of the transient flow of helium in an expansion tube. The aim of the exercise is to provide further information on and hopefully further insight into the operational problems of the NASA Langley expansion tube. The calculations were performed with an axisymmetric Navier-Stokes code based on a finite-volume formulation and upwinding techniques. Although laminar flow and ideal bursting of the diaphragms was assumed, the simulations showed some of the important features seen in the experiments. In particular, the discontinuity in tube diameter at the primary diaphragm station introduced a transverse perturbation to the expanding driver gas and this perturbation was seen to propagate into the test gas under some flow conditions. The disturbances seen in the test flow can be characterized as either small-amplitude noise possibly introduced during shock compression or large-amplitude noise associated with the passage of the reflected head of the unsteady expansion. Expansion tube, Numerical simulation.

Descriptors:

• *SHOCK TUBES
• *FLOW
• TRANSIENTS
• DIAMETERS
• VOLUME
• FORMULATIONS
• SHOCK
• AXISYMMETRIC
• HELIUM
• EXPANSION
• NOISE
• UNSTEADY FLOW
• DISCONTINUITIES
• LAMINAR FLOW
• TRANSVERSE
• COMPRESSION
• SIMULATION

Subject Categories:

• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE