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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Hypersonic laminar viscous interaction effects on aerodynamics of two-dimensional wedge and triangular planform wings
Hypersonic static stability investigation of Tomahawk rocket model
Atmospheric argon effect on hypersonic stagnation point convective heat transfer, using arc-heated shock tube simulating flight velocities up to 34,000 fps
Arc-driven vortex type heater-accelerator for possible use in reentry flight simulation
Optimum hypersonic lifting wings
Attached and separated boundary layers on highly cooled, ablating and nonablating models at Mach 13.8
Aerodynamic nonlinearity of hypersonic panel
Aerodynamic heating in vicinity of corners at hypersonic speeds
Atmospheric argon effect on hypersonic stagnation point convective heat transfer, using arc-heated shock tube simulating flight velocities up to 34,000 fps
Similar calculation of hypersonic laminar boundary layer characteristics in presence of pressure gradient, specifically heat transfer, skin friction and boundary layer thickness
Viscous degradation of hypersonic lift-drag ratio in manned spacecraft, noting free stream Mach and Reynolds numbers
Comparison of schlieren and phase contrast methods for visualization of aerodynamic flow at hypersonic velocities
For the interaction of shock waves with turbulent boundary layers, obtained experimental three-dimensional separation results and correlations with earlier two-dimensional and three-dimensional data are presented. It is shown that separation occurs much earlier for turbulent three-dimensional than for two-dimensional flow at hypersonic speeds.
Computer programs calculate two-dimensional patterns for six types of supersonic and hypersonic interference flow fields and surface heating.
An over-relaxation procedure is applied to the MacCormack finite-difference scheme in order to reduce the computation time required to obtain a steady-state solution. The implementation of this acceleration procedure to an existing computer program using the regular MacCormack method is extremely simple and does not require additional storage. The over-relaxation procedure does not alter the steady-state solution, which is second-order accurate. The method is first applied to Burgers' equation. A stability condition and an expression for the increase in the rate of convergence are derived. The method is then applied to the calculation of the hypersonic viscous flow over a flat plate, using the complete Navier-Stokes equations, and the inviscid flow over a wedge. Reductions in computing time by factors of 3 and 1.5, respectively, are obtained by over-relaxation.
The paper examines the applicability of the three-step Stetter (1968) method to the problem of hypersonic viscous flow over a blunt axisymmetric body used for planetary entry probes at zero angle of attack. The flow-field results using the two-step finite-difference MacCormack (1969) method are reported by Kumar and Graves (1977). Only the computational efficiency of Stetter's method is compared with that of MacCormack's in terms of the iterative time steps and computing time required for the steady-state solution. Advantages of Stetter's method over MacCormack's are established.
The aeronautical R & D effort in NASA is discussed with emphasis on those areas where major needs and opportunities exist. In aerodynamics, areas selected for discussion include computational aerodynamics, transonic test techniques, high Reynolds number research, skin friction drag reduction, and propulsive lift. In propulsion, consideration is given to the areas of fuel-efficient subsonic propulsion, variable-flow engines, hypersonic propulsion, alternate fuels, and aircraft noise reduction. Consideration is also given to the utilization of advanced composites and integrated avionic systems.
MacCormack's implicit finite-difference scheme was used to solve the two-dimensional parabolized Navier-Stokes (PNS) equations. This method for solving the PNS equations does not require the inversion of block tridiagonal systems of algebraic equations and permits the original explicit MacCormack scheme to be employed in those regions where implicit treatment is not needed. The advantages and disadvantages of the present adaptation are discussed in relation to those of the conventional Beam-Warming scheme for a flat plate boundary layer test case. Comparisons are made for accuracy, stability, computer time, computer storage, and ease of implementation. The present method was also applied to a second test case of hypersonic laminar flow over a 15% compression corner. The computed results compare favorably with experiment and a numerical solution of the complete Navier-Stokes equations.