Reynolds number and Mach number effect on space shuttle configurations

Analytical studies have been conducted concerning the lee-surface flow phenomena over a space shuttle orbiter model based on the experimental data obtained during September, 1971 through August, 1972. Lee-surface peak heating phenomena and flow separation patterns were analyzed. Major results of analyses are briefly presented

Theoretical investigation of crossflow effects on compressible turbulent boundary layer over bodies of revolution

Crossflow effects on compressible turbulent boundary layer over bodies of revolutio

Sonic boom research

A computer program for CDC 6600 is developed for the nonlinear sonic boom analysis including the asymmetric effect of lift near the vertical plane of symmetry. The program is written in FORTRAN 4 language. This program carries out the numerical integration of the nonlinear governing equations from the input data at a finite distance from the airplane configuration at a flight altitude to yield the pressure signitude at ground. The required input data and the format for the output are described. A complete program listing and a sample calculation are given

Skin friction reduction by slot injection at Mach 0.8

Surface skin friction, boundary layer profiles and turbulent intensity due to axially symmetric tangential slot injection into a transonic boundary layer were measured. Effects of slot height, multiple slot injection, and injection mass flow rate on the surface skin friction downstream of the the slot have been investigated. Surface skin friction was a function of the injection mass flow rate for x/s 40. Large normal pressure gradient and relatively large turbulent intensity were found near the slot with small injection mass flow rate; the region the high turbulent intensity moved downstream with increasing injection mass flow rate. The results with two slot injections indicated that the distance between slots should be less than 30 slot heights in order to achieve some benefits from the first slot. Of significant importance in the present investigation is that the skin friction reduction obtained at transonic speed is of the same order as obtained in the hypersonic regime. Additional work is required in order to formulate a correlation between the turbulent intensity and the injection mass flow rate that may be used in future analysis

An experimental investigation of vortex generation in a turbulent boundary layer undergoing adverse pressure gradient

The existence of streamwise vortices in nominally 2-dimensional boundary layers undergoing adverse pressure gradient was investigated. The free stream Mach number was 5.75, the wall to stagnation temperature ratio was 0.63 and the Reynolds number based on free stream conditions was 3.9 x 10 to the 7th power/ft. The model consisted of an axisymmetric compression flare preceded by a cylindrical axially symmetric body. A natural turbulent boundary layer was established well ahead of the compression region. Boundary layer profiles of static pressure, pitot pressure, and stagnation temperature were taken at a surface station with a local inclination of 20 deg. Profile measurements were obtained at various peripheral stations. The measurements revealed zero peripheral variations at the surface of the body and at the edge of the boundary layer. However, distinct wavy pressure variations were observed within the boundary layer profiles, indicating the existence of longitudinal vortex cells within the boundary layer

Lee surface flow phenomena over space shuttle at large angles of attack at M sub infinity equal 6

Surface pressure and heat transfer, flow separation, flow field, and oil flow patterns on the leeward side of a space shuttle orbiter model are investigated at a free stream Mach number of 6. The free stream Reynolds numbers are between 1.64 times 10 to the 7th power and 1.31 times 10 to the 8th power per meter, and the angle of attack is varied between 0 deg and 40 deg for the present experiments. The stagnation temperatures for the tests are approximately 500 K and the wall temperature is maintained at 290 K. Existing numerical methods of three-dimensional inviscid supersonic flow theory and compressible boundary layer theory are used to predict the present experimental measurements. Results of the present tests indicate two distinct types of flow separation and surface peak heating depending on the angle of attack

An experimental and analytical investigation of the aerodynamics of a hypersonic vehicle at free stream Mach 6

The goal of this research is the assessment of the validity of existing three dimensional numerical programs in the prediction of the flow fields about general three dimensional hypersonic bodies. A detailed experimental research program was performed in which surface and flow field pressures were mapped. The results of the experimental work were compared with existing inviscid programs. Improvements were made on the existing numerical methods to include angle of attack. A summary of this work is presented

Experimental investigation of fuel vaporization on combustion efficiency

The development of a residential size vaporizing oil burner is presented along with its operational and performance characteristics. The vaporization scheme consists of spraying No. 2 oil onto a regeneratively heated surface at a temperature above the oil vaporization temperature (650/sup 0/F). The vaporized oil mixes with a preheated air (T = 250/sup 0/F) stream to produce a uniform fuel air mixture. The premixed vaporized fuel/air stream produces short blue flamelets anchored to a steel screen flame holder. The operational and performance characteristics of this burner are presented for a range of the air and oil flow parameters around the stoichiometric condition, and for a nominal firing rate of less than or equal to 1.2 gph. Operation with less than 3% excess air is demonstrated with very little soot formation. The combustion quality of the vaporizing oil burner is substantially improved compared to conventional spray combustion and recirculation type blue flame burners. The vaporizing oil burner was adapted to a conventional boiler and the thermal efficiency was determined by a calorimeter technique and compared to the stack method. The thermal efficiency with the vaporized combustion mode is about 4% greater than conventional spray combustion burners. The increase is realized through the reduced excess air requirements. The increased efficiency can result in reduced oil consumption from 12% to 20% depending on the location and usage of the burner unit