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Using reasonable assumptions for turbomachinery efficiencies and heat exchanger effectivenesses, the Coefficient of Performance (COP) and Specific Heating Effect (SHE) of the regenerated and unregenerated cycles are computed and optimized. Only heating data are presented and both open and closed cycles are considered. An effort is made to indicate those cases where (the working fluid being air) the cycle may be appropriately open to combine the heating function with ventilation. When driven by an appropriately small direct Brayton cycle prime mover, the total potential for a new and widespread gas turbine application of literally millions of units becomes defined.

Turbomachine blades on spinning and precessing rotors experience gyroscopically induced instabilities and forcing. With vehicle-mounted turbomachines, either constant or harmonic precession occurs, depending on vehicle or mount motion. Responses of uniform cantilever beams at arbitrary stagger, subjected to the noted rotor motion, are predicted in both self-excited and forced-excitation modes taking into account Coriolis acceleration.

The “time marching” technique is successfully applied to the numerical computation of the nonstationary aerodynamics of a flat plate cascade for compressible flow of either subsonic or supersonic nature. The unsteady perturbation amplitudes of fluid properties are used as the dependent variables so that the computational domain can be reduced to a two-dimensional channel guided by two adjacent blades for any interblade phase angle. A new method of handling the boundary condition is developed in which the order of accuracy for the boundary points will be the same as the interior points. The wake region behind the trailing edge of each blade is treated as a “slip plane” as done in two-dimensional steady state supersonic flow. Results are in good agreement with existing analytical solutions.

An analytical method for predicting the perturbed aerodynamic reactions of a harmonically oscillating flat plate airfoil with time dependent point of separation is presented. It is shown that this method in conjunction with an empirical knowledge of the time history of the separation point can predict stall-flutter. Numerical results are presented and compared with existing theoretical and experimental results with special emphasis on torsional mode of oscillation.

The Saint Venant torsion problem is solved for a region bounded by two circular arcs forming a crescent. The region is conformally transformed to an infinite strip and the stress function is obtained by Fourier integral. Subsequent quadratures for evaluation of the torsion constant are obtained explicitly with the exception of a single infinite integral which may easily be evaluated numerically. Some values of the torsion constant are given, and an approximate formula valid for small “camber” is presented.