Linearized Theory of Gas-Dynamic-Laser Nozzle Wakes and Applications.

摘要

This report presents formulas describing laminar and turbulent wake behavior for various nozzle exit Mach and Reynolds numbers, specific heat ratios and nozzle wall temperatures. Such generality is achieved by 'standardizing' the nozzle contour and utilizing the linearized, similarity approach to wake flow. For laminar wakes this linearized solution has been available for some time. A corresponding solution has been available for the turbulent wake, with the transport coefficients given from experiments on two-dimensional supersonic wakes. The disadvantage of the linearized solution is its invalidity near the cusp trailing edge, and also when the design parameters lie on certain extreme ranges. The advantage lies in the compactness with which the results are expressed in charts and tables. Also, the qualitative trends in wake behavior with changing parameter values should not then change much if non-linear, exact solutions were to be found.