Pressure measurement in the study of an aerodynamic window for high-energy lasers

The beam from a high-energy laser must be emitted through a special window which shields the laser cavity from the surrounding atmosphere.

The beam from a high-energy laser must be emitted through a special window which shields the laser cavity from the surrounding atmosphere. In order to reduce the disadvantages arising from the thermal loading of the window material, an aerodynamic window was used which consisted of a supersonic free-jet of nitrogen.

This article describes the experimental proof of the functionability of this window. The main points of the research were the measurement of pressure profile in the free-jet and the pressure along the diffuser wall. Measurements were made by means of strain-gage based absolute pressure transducers. Specially designed adapters assured that the pressures at the desired measuring points could be measured.