Experimental Investigation of the Starting Process of Short Diffusers for Gas Dynamic Lasers.
Abstract
The diffuser section of a Gas Dynamic Laser (GDL) is one of the largest components in the system. The purpose of this investigation was to examine the problem of starting supersonic flow in short diffusers with fixed walls, incorporating various bleed arrangements for boundary layer control (BLC). A Mach number of 4, ramp angle of 19 degrees diffuser length of 4.5 inches and a diffuser width of 1.0 inch were used throughout this investigation. Intrusion by the atmosphere into the diffuser causes a separation region or bubble to form. The presence of this 'bubble' could be made to improve the diffuser performance by making a variable area diffuser out of a fixed wall diffuser without the use of any external apparatus. BLC was helpful in increasing the over all pressure recovery of the diffuser. BLC also affects the unsteady flow, which was present in the diffuser, but only when it is applied at a point prior to the converging section of the GDL. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1975
- Accession Number
- ADA014556
Entities
People
- Milford Merwin Oudekerk
Organizations
- Naval Postgraduate School