Accession Number:

AD0700778

Title:

AN INVESTIGATION OF PLANAR FREE JETS.

Descriptive Note:

Interim technical rept.,

Corporate Author:

OHIO STATE UNIV COLUMBUS AERONAUTICAL AND ASTRONAUTICAL RESEARCH LAB

Personal Author(s):

• Bittner,Jay W.
• Gregorek,Gerald M.

Report Date:

1969-11-01

Pagination or Media Count:

40.0

Abstract:

Suggested use of highly underexpanded free jets for hypersonic, low density facilities has led to an analytic and experimental study of planar free jets. Tests with sonic slot nozzles showed strong oblique shocks emanating from the ends. The shocks dominated the expansion process, and terminated the isentropic flow far upstream of a theoretical location for a normal shock, even for a slot of length-to-width ratio of 200. Side plates reduced these end effects, increasing the isentropic region by moving the shock system downstream. The two-dimensional method of characteristics was employed to study planar expansions from slot nozzles of three different exit Mach numbers operating at different pressure ratios. Surface pressures taken from the side plates agree well with predictions from the characteristics theory, until the isentropic expansion is ended by shocks caused by boundary layer separation from the side plates. Author

Descriptors:

• (*NOZZLE GAS FLOW
• *JETS)
• DENSITY
• HYPERSONIC CHARACTERISTICS
• HIGH ALTITUDE
• AERODYNAMIC SLOTS
• TEST FACILITIES
• SHOCK WAVES
• PRESSURE
• BOUNDARY LAYER
• FLOW SEPARATION

Subject Categories:

• Aerodynamics
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE