Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “CONE”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Computer program for calculating supersonic flow about circular, elliptic, and bielliptic cones by the method of lines

A user's manual for a computer program which calculates the supersonic flow about circular, elliptic, and bielliptic cones at incidence and elliptic cones at yaw by the method of lines is presented. The program is automated to compute a case from known or easily calculated solution by changing the parameters through a sequence of steps. It provides information including the shock shape, flow field, isentropic surface properties, entropy layer, and force coefficients. A description of the program operation, sample computations, and a FORTRAN 4 listing are presented.

Klunker, E. B.↗
NASA NTRS1972

Hypersonic rarefied flow over sharp slender cones

Drag, heat transfer, and number flux were measured on sharp cones in the near free, molecule flow regime, and the results were compared with available Monte Carlo calculations. In general, the calculations predicted the magnitude of the data; however, the heat transfer and drag increased with increasing Knudsen number at a faster rate than predicted. Also the drag coefficients measured for the slender cones at high Knudsen number were higher than predicted for free molecule flow. These disagreements between theory and experiment could possibly be attributed to the simplicity of the surface interaction laws assumed in the theory. Reynolds analogy factors obtained from the experimental measurements agreed with free-molecule values and also with that obtained by the Monte Carlo technique.

Kussoy, M. I.↗
NASA NTRS1972

Experimental damping-in-pitch of two slender cones at Mach 2 and incidences up to 30 deg

Oscillatory experiments were performed on two slender cones at Mach 2 and incidences up to 30 deg, using three different experimental arrangements. The damping-in-pitch was found to remain constant at incidences of up to a value approximately corresponding to the cone semi-angle, after which an almost linear increase with incidence was noted. The results obtained with the different techniques were in very good agreement up to an incidence of 15 deg and in some cases up to 25 deg.

Iyenger, S.↗
NASA NTRS1972

Application of boron/epoxy reinforced aluminum stringers and boron/epoxy skid gear for the CH54B helicopter tail cone. Phase 2: Fabrication, inspection and flight test

A CH-54B Skycrane helicopter was fabricated with boron/epoxy reinforced stringers in the tail cone and boron/epoxy tubes in the tail skid. The fabrication of the tail cone was made with conventional tooling, production shop personnel, and no major problems. The flight test program includes a stress and vibration survey using strain gages and vibration transducers located in critical areas. The program to inspect and monitor the reliability of the components is discussed.

Welge, R. T.↗
NASA NTRS1972

A generalized theory for the design of contraction cones and other low speed ducts

A generalization of the Tsien method of contraction cone design is described. The design velocity distribution is expressed in such a form that the required high order derivatives can be obtained by recursion rather than by numerical or analytic differentiation. The method is applicable to the design of diffusers and converging-diverging ducts as well as contraction cones. The computer program is described and a FORTRAN listing of the program is provided.

Barger, R. L.↗
NASA NTRS1972

Free flight determination of boundary layer transition on small scale cones in the presence of surface ablation

To assess the possibility of achieving extensive laminar flow on conical vehicles during hyperbolic entry, the Ames Research Center has had an ongoing program to study boundary-layer transition on ablating cones. Boundary layer transition results are presented from ballistic range experiments with models that ablated at dimensionless mass transfer rates comparable to those expected for full scale flight at speeds up to 17 km/sec. It was found possible to measure the surface recession and hence more accurately identify regions of laminar, transitional, and turbulent flow along generators of the recovered cones. Some preliminary results using this technique are presented.

Wilkins, M. E.↗
NASA NTRS1973

Tables for Supersonic Flow of Helium Around Right Circular Cones at Zero Angle of Attack

The results of the calculation of supersonic flow of helium about right circular cones at zero angle of attack are presented in tabular form. The calculations were performed using the Taylor-Maccoll theory. Numerical integrations were performed using a Runge-Kutta method for second-order differential equations. Results were obtained for cone angles from 2.5 to 30 degrees in regular increments of 2.5 degrees. In all calculations the desired free-stream Mach number was obtained to five or more significant figures.

Sims, J. L.↗
NASA NTRS1973

Lunar cinder cones.

Data on terrestrial eruptions of pyroclastic material and ballistic considerations suggest that in the lunar environment (vacuum and reduced gravity) low-rimmed pyroclastic rings are formed rather than the high-rimmed cinder cones so abundant on the earth. Dark blanketing deposits in the Taurus-Littrow region (Apollo 17 landing area) are interpreted as being at least partly composed of lunar counterparts of terrestrial cinder cones.

Mcgetchin, T. R.↗
NASA NTRS1973

Laminar film condensation on the inside of slender, rotating truncated cones.

A solution for film condensation on the inside of slender rotating truncated cones is established in the region where the half cone angle phi is close to zero and where the equation of Dhir and Lienhard (1971) is no longer valid. All the familiar assumptions used in Nusselt's theory of laminar film condensation are assumed valid, including negligible sub-cooling and momentum changes in the condensate film, no interfacial shear between the condensate and the vapor, and pure conduction within the condensate film. A Runge-Kutta numerical integration method using a digital computer was used. Results for a specific geometry are given for water condensing at 212 F on a condenser wall maintained at 70 F.

Marto, P. J.↗
NASA NTRS1973

Unsteady aerodynamic loads on slender cones at free-stream Mach numbers from 0 to 22.

Results of an experimental study to determine the flow-induced unsteady aerodynamic loads on slender cones at very high Mach numbers. Experiments on 8-deg half-angle-cone/flat-base configurations were conducted at free-stream Mach numbers of 6 and 15 and Reynolds numbers corresponding to shuttle reentry conditions. The flow facilities used were the H-3 Hypersonic Facility (Mach 6) and the Longshot Free Piston Tunnel (Mach 15) of the Von Karman Institute for Fluid Dynamics in Rhode-St.-Genese, Belgium. With these test results and pertinent results from other research efforts, data were available at free-stream Mach numbers of 0.67, 2.5, 3, 4, 6, 15, and 22, so that empirical expressions could be developed for the Mach number dependence (1) of the overall fluctuating pressure under an attached turbulence boundary layer and (2) of the overall fluctuating base pressure.

Heller, H. H.↗
NASA NTRS1973

Measured pressure distributions of large-angle cones in hypersonic flows of tetrafluoromethane, air, and helium

An experimental study of surface pressure distributions on a family of blunt and sharp large angle cones was made in hypersonic flows of helium, air, and tetrafluoromethane. The effective isentropic exponents of these flows were 1.67, 1.40, and 1.12. Thus, the effect of large shock density ratios such as might be encountered during planetary entry because of real-gas effects could be studied by comparing results in tetrafluoromethane with those in air and helium. It was found that shock density ratio had a large effect on both shock shape and pressure distribution. The differences in pressure distribution indicate that for atmospheric flight at high speed where real-gas effects produce large shock density ratios, large-angle cone vehicles can be expected to experience different trim angles of attack, drag coefficient, and lift-drag ratios than those for ground tests in air wind tunnels.

Jones, R. A.↗
NASA NTRS1973

A generalized technique for using cones and dihedral angles in attitude determination, revision 1

Analytic development is presented for a general least squares attitude determination subroutine applicable to spinning satellites. The method is founded on a geometric approach which is completely divorced from considerations relating to particular types and configurations of onboard attitude sensors. Any mix of sensor measurements which can be first transformed (outside the program) to cone or dihedral angle data can be processed. A cone angle is an angle between the spin axis and a known direction line in space; a dihedral angle is an angle between two planes formed by the spin axis and each of two known direction lines. Many different kinds of sensor data can be transformed to these angles, which in turn constitute the actual program inputs, so that the subroutine can be applied without change to a variety of satellite missions. Either a constant or dynamic spin axis model can be handled. The program is also capable of solving for fixed biases in the input angles, in addition to the spin axis attitude solution.

Werking, R. D.↗
NASA NTRS1974

Vortex-induced heating to cone flaps at Mach 6

Discussion of the local heating effect on the lee-side control flaps of supersonic configurations due to the interaction between vortices and leeward control surfaces at an angle of attack. Considerations are given for an appropriate positioning of control flaps to alleviate such interactions and the resulting thermal effect. Tests are carried out on a sharp right circular cone with two types of flap configurations in a study of oil flow patterns about the cone at selected angles of attack. Splitting of flaps and moving them to positions away from the symmetry plane did reduce the heating but also reduced the average flap pressure and increased flow complexity.

Hefner, J. N.↗
NASA NTRS1975

The X-band low noise antenna measurement cone

An X-band low-noise receiving cone with 17-MHz instantaneous bandwidth was built to evaluate the 26-m antenna at the Venus Station (DSS 13), Goldstone, California, at X-band frequencies, and also to provide a means for precise radio source calibrations in this frequency range. These measurments are necessary to provide more accurate antenna gain performance calibrations for the 64-m antenna subnet. The zenith system temperatures with the cone on the ground and on the antenna are 17.5 and 20.8 K, respectively.

Reid, M. S.↗
NASA NTRS1976

Prepared comment on the cone transition Reynolds number data correlation study

A sharp, smooth, 10-deg-included-angle cone was tested on twenty-one major wind tunnels of the United States and Western Europe to obtain correlation data on the effect of acoustic disturbances in wind tunnel flow on boundary layer transition Reynolds number. The cone is planned to be flight tested in order to obtain a basis of reference for the wind tunnel data over a nominal range of Mach numbers from 0.4 to approximately 2.0. Wind tunnel data obtained over a Mach number range from 0.2 to 4.6 are broadly characterized according to wind tunnel test section geometry and, in turn, to the types of acoustic disturbances associated with the geometry.

Dougherty, N. S., Jr.↗
NASA NTRS1977

Heat-transfer test results for a .0275-scale space shuttle external tank with a 10 deg/40 deg double cone-ogive nose in the NASA/AMES 3.5-foot hypersonic wind tunnel (FH14), volume 2

A .0275 scale forebody model of the new baseline configuration of the space shuttle external tank vent cap configuration was tested to determine the flow field due to the double cone configuration. The tests were conducted in a 3.5 foot hypersonic wind tunnel at alpha = -5 deg, -4.59 deg, 0 deg, 5 deg, and 10 deg; beta = 0 deg, -3 deg, -5.51 deg, -6 deg, -9 deg, and +6 deg; nominal freestream Reynolds numbers per foot of 1.5 x 1 million, 3.0 x 1 million, and 5.0 x 1 million; and a nominal Mach number of 5. Separation and reattached flow from thermocouple data, shadowgraphs, and oil flows indicate that separation begins about 80% from the tip of the 10 deg cone, then reattaches on the vent cap and produces fully turbulent flow over most of the model forebody. The hardware disturbs the flow over a much larger area than present TPS application has assumed. A correction to the flow disturbance was experimentally suggested from the results of an additional test run.

Carroll, H. R.↗
NASA NTRS1977

Investigation of real-gas and viscous effects on the aerodynamic characteristics of a 40 deg half-cone with suggested correlations for the shuttle orbiter

Parameters were evaluated that might be used to correlate shuttle orbiter aerodynamic data to be used in extrapolating from wind-tunnel to flight conditions. Preliminary calculations indicate that the lee-side forces will have an insignificant influence on the aerodynamic characteristics of the orbiter for moderate angle-of-attack entries; therefore, this work is focused on phenomena which have an overriding influence on windward forces, namely, real-gas (equilibrium and nonequilibrium) and viscous-interaction effects. Analytically determined flow fields previously obtained on 40 deg blunted cones were used as a data source to evaluate various correlation parameters. Inviscid effects were found to be the dominant contributor to the aerodynamic coefficients in the altitude range of 64 to 76.2 km. The most suitable correlation of the aerodynamic forces on these cones is based on local dynamic pressure and local Mach number.

Hunt, J. L.↗