An Investigation Of Sheet Stiffener Panels Subjected To Compression Loads With Particular Reference To Torsionally Weak Stiffeners

Analytical methods are developed that make it possible for the designer to predict with reasonable accuracy the buckling stress and the maximum-wave amplitude of the sheet in stiffened-panel combinations. The scope of the tests was insufficient to formulate general design criteria but the results are presented as a guide for design and an indication of the type of theoretical and experimental work needed.

Analytical methods are developed that make it possible for the designer to predict with reasonable accuracy the buckling stress and the maximum-wave amplitude of the sheet in stiffened-panel combinations. The scope of the tests was insufficient to formulate general design criteria but the results are presented as a guide for design and an indication of the type of theoretical and experimental work needed.

An experimental investigation was conducted in order to determine the performance of a 90 degree cascade diffusing bend with an area ratio of 1.45:1 and a 19-inch square inlet with several inlet-boundary-layer shapes and thicknesses. The maximum mean inlet Mach number was 0.41 and the corresponding airfoil Reynolds number was 950,000. The experimental results seem to indicate that, when the duct configuration requires a bend, a certain amount of diffusion can be obtained without an appreciable rise in the total-pressure losses. If length is important, this configuration requires much less space than the usual diffuser-bend combination.