Effect Of Nose Bluntness Research Articles

Comments on 'Effect of nose bluntness and cone angle on slender-vehicle transition'

Comments on 'Effect of nose bluntness and cone angle on slender-vehicle transition'

Aerothermodynamic study of slender conical vehicles

A numerical study was performed to assess the applicability of some current techniques which can be used for aerothermal predictions over slender spherically blunted cones. Predictions using a viscous-shock-layer method and several engineering approaches were compared with experimental results from flight and ground-based tests, with each other, and with other detailed results. Good agreement was obtained in comparisons with laminar and turbulent heating data from the Reentry F flight vehicle and with the wind-tunnel data. In particular, the viscous-shock-layer method was shown to yield excellent comparisons and should be useful in providing detailed flowfield and surface values for slender blunted cones. Additional predictions were obtained with these methods for two 5-deg half-angle cones with different nose radii to illustrate the effects of nose bluntness and angle of attack on drag and heat transfer. These results demonstrate the benefit of nose blunting with respect to heating and drag for laminar and transitional flow at zero-lift conditions and the benefit of heating reduction at angle of attack. Detailed comparison of the engineering code predictions with the viscous-shock-layer results for these additional cases generally showed good agreement except for the laminar prodictions at angle of attack on the forward cone surface. Nonequilibrium calculations at 0-deg angle of attack showed that substantial benefits of low surface catalysis existed only in the nose-dominated region.

Effect of nose bluntness and cone angle on slender-vehicle transition

L'analyse des resultats experimentaux demontre que l'effet d'une geometrie en cone elance sur la transition de couche limite est d'origine non visqueuse. Consequences pratiques pour la conception de vehicules aerodynamiques

Parametric investigations of slender cone nose bluntness effects

Parametric investigations of slender cone nose bluntness effects

Computational study of nose bluntness effects for spinning shells atsupersonic speeds

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Lifting and nonlifting kernel functions for cascade and isolated airfoils

References 1 East, R. A., Qasrawi, A. M., and Khalid, M., An Experimental Study of the Stability of Pitching Blunt Conical and Hyperballistic Shapes in a Short Running Time Facility, AGARD Conference Proceedings, No. 235, Nov. 1978. Khalid, M. and East, R. A., ''Stability Derivatives of Blunt Slender Cones at High Mach Numbers, Aeronautical Quarterly, Vol. 30, Nov. 1979, pp. 559-590. Eggers, A. J. and Savin, R. C., A Unified Two-Dimensional Approach to the Calculation of Three-Dimensional Flows with Application to Bodies of Revolution, NACA Rept. 1249, 1955. Stone, A. H., On Supersonic Flow Past a Slightly Yawing Cone, II, Journal of Math & Physics, Vol. 30, 1951, pp. 200-213. Kopal, Z., Tables of Supersonic Flow around Cones at Large Yaw, M.I.T. TR. No. 5, 1949. Taylor, G. I. and Maccoll, J. W., Air Pressure on a Cone Moving at High Speeds, Proceedings of the Royal Society of London, Series A, Vol. 139, Feb. 1933, pp. 278-311. Khalid, M., A Theoretical and Experimental Study of the Stability of Blunt Axisymmetric Conical and Power Law Shapes, Ph.D. Thesis, University of Southampton, Hants, England, 1977. Schueler, C. J., Dynamic Stability Results for a 10 deg Cone at Mach Numbers 0.8 to 20, AEDC-TDR 64-226, Dec. 1964. Marshall, L. A., Hypersonic Stability Summary, Pt. 1, Tech. Rept. AFFDL-TDR 66-149, Jan. 1967. Qasrawi, A. M., Unpublished data, University of Southampton, Hants, England, 1978. Ericsson, L. E., Effect of Nose Bluntness, Angle of Attack, and Oscillation Amplitude on Unsteady Aerodynamics of Slender Cones, AIAA Journal, Vol. 9, Feb. 1971, pp. 297-304.

Stability Derivatives of Blunt Slender Cones at High Mach Numbers

SummaryThis paper presents a semi-empirical theoretical model for calculating the effect of nose bluntness on the stability derivatives of oscillating slender cones at hypersonic Mach numbers. It is based on a hybrid blast wave analogy/shock-expansion flow model and is used to obtain closed form analytic expressions for the derivatives for oscillating slender cones. Two models based on zero thickness and finite thickness entropy layers are proposed which are seen to be appropriate to the cases of very small and large nose bluntnesses, respectively. The results are compared with new and existing experimental data and with the predictions of previous theoretical methods.

ガン・タンネルによる鈍頭円すいの圧力測定実験

The pressure distributions on sphericallyblunted cones, which are installed in test section as axisymmetric condition, are measured in the hypersonic flows produced with contour and conical nozzles of the NAL gun tunnel. The experimental results of pressure coefficient are successfully correlated by the blast-wave-type parameters Cp/Cconep and (θcθc2/√CDn)/(xn/dn). The effect of nose bluntness on the pressure distribution of a blunted cone in inviscid hypersonic flow is clarified, by taking into account of viscous induced pressure included in the experimental results.It is also shown that the pressure distribution on models tested in conical nozzle is appreciable difference as compared With that tested in contour nozzle, but they are in good agreement with each other according to the source flow correction method proposed in the present paper.Detailed discussion about various effects, such as those of temperature and vibration, on pressure transducer is given for the measurement of low pressure.

Study of Base Pressure in Laminar Hypersonic Flow: Re-entry Flight Measurements

Base pressure data from flight tests of four full-scale re-entry vehicles are analyzed. The flight vehicles were nearly identical, slightly blunted, 9° half-angle sphere cones. Flow conditions were hypersonic, M^ * 16-20, and the cone boundary layer and near wake were laminar for Reynolds numbers Re L between 2 X10 and 5 x 1C. The flight data are compared with available theory and groundand flight-test data for similar configurations. Various correlation parameters, derived from both experimental ground-test and theoretical results, are utilized in this analysis. Suitable data correlations, were obtained with the reduced Reynolds number suggested by Wu and Su and with parameters from the Reeves and Buss theory. Correlations of the present data are directed toward establishing a basis for re-entry vehicle preflight predictions and postflight data analyses. Resulting base pressure calculations for other slender configurations (7°, 8°, and 10° cones) in hypersonic entry conditions show good agreement with both theory and flight data and indicate the importance of including real-gas and nose-bluntness effects in high Reynolds-number laminar flows.

Combined Effects of Nose Bluntness and Cone Angle on Unsteady Aerodynamics

Combined Effects of Nose Bluntness and Cone Angle on Unsteady Aerodynamics

Effects of nose bluntness, angle of attack, and oscillation amplitude on hypersonic unsteady aerodynamics of slender cones

A previously developed analytic theory for the unsteady aerodynamics of moderately blunt slender cones has been extended to include the effects of large nose bluntness, nonzero angles of attack, and finite oscillation amplitudes. It is shown that the developed theory agrees well with available experimental data and correctly predicts the opposite effects of nose bluntness on static and dynamic stability including the highly nonlinear characteristics at angles of attack and oscillation amplitudes up to cone half-angle magnitudes. A universal scaling law has been derived that gives the nose-bluntness effects on static and dynamic characteristics for the above angle-of-attack and amplitude ranges with sufficient accuracy for preliminary design of conical re-entry vehicles flying ballistic or lifting re-entry trajectories.

Interaction of sonic transverse jets with supersonic external flows

11 Griffith, B. J. and Lewis, C. H., A Study of Laminar Heat Transfer to Spherically Blunted Cones and Hemisphere-Cylinders at Hypersonic Conditions, AEDC-TDR-63-102, June 1963, Arnold Engineering Development Center. 12 Wagner, R. D., Jr. and Watson, R., Induced Pressures and Shock Shapes on Blunt Cones in Hypersonic TND-2182, March 1964, NASA. 13 Friberg, E. G., Pressure Distribution on a 5.6° Blunt Cone at Mach 14, ARL 68-02,08, Nov. 1968, Aerospace Research Lab. 14 Ericsson, L. E., Separated Flow Effects on the Static and Stability of Blunt Nosed Cylinder Flare Bodies, LMSC-667991, Contract NAS 8-5338, Dec. 1965, Lockheed Missiles & Space Co., Sunny vale, Calif. 15 Ericsson, L. E. and Reding, J. P., Dynamic Stability Problems Associated with Flare Stabilizers and Flap Controls, Journal of Spacecraft and Rockets, Vol. 7, No. 2, Feb. 1970, pp. 132-137. 16 Walchner, O. and Clay, J. T., Bluntness Effects on the Stability Derivatives of Cones in Hypersonic Flow, Transactions of the Second Technical Workshop on Stability Testing, Vol. 1, Paper 8, April 1965, Arnold Engineering Development Center, Arnold Air Force Station, Tenn. 17 Ericsson, L. E., Effect of Boundary Layer Transition on Vehicle Dynamics, Journal of Spacecraft and Rockets, Vol. 6, No. 12, Dec. 1969, pp. 1404-1409. 18 Rainbird, W. J., Turbulent Boundary-Layer Growth and Separation on a Yawed Cone, AIAA Journal, Vol. 6, No. 12, Dec. 1968, pp. 2410-2416. 19 Clay, J. T., Bluntness, Cone Angle, and Mach Number Effects on the Stability Derivatives of Slender Cones, ARL 67-0185, Sept. 1967, Aerospace Research Lab. 20 Ward, L. K, Jr. and Uselton, B. L., Dynamic Stability Results for Sharp and Blunted 10-deg Cones at Hypersonic Speeds, Transactions of the 3rd Technical Workshop on Stability Problems, Vol. Ill, Paper 2, Nov. 1968, NASA. 21 Ericsson, L. E. and Scholnick, I. M., Effect of Nose Bluntness on the Hypersonic Unsteady Aerodynamics of Flared and Conical Bodies of Revolution, Journal of Spacecraft and Rockets, Vol. 6, No. 3, March 1969, pp. 321-324. 22 Friberg, E. G. and Walchner, O., Pressure Correlation for Blunted Slender Cones, AIAA Journal, Vol. 7, No. 8, Aug. 1969, pp. 1618-1619. 23 Ericsson, L. E., Universal Scaling Laws for Nose Bluntness Effects on Hypersonic Unsteady Aerodynamics, AIAA Journal, Vol. 7, No. 12, Dec. 1969, pp. 2222-2227.

Combined effects of mass addition and nose bluntness on boundary-layer transition

Cone boundary layer transition location and Reynolds number as function of nose bluntness combined effect with Ar, air and He mass injection

Real gas effects on shock-tube flow nonuniformity

3 Dernetriades, A., An Investigation of the Stability of the Laminar Layer, Memo 43, 1958, Guggenheim Aeronautical Lab., California Institute of Technology. 4 Potter, J. L. and Whitfield, J. D., Effects of Unit Reynolds Number, Nose Bluntness, and Roughness on Layer Transition, TR-60-5, 1960, Arnold Engineering Development Center. 5 Nagamatsu, H. T., Graber, B. C., and Sheer, R. E., Jr., Critical Layer Concept Relative to Layer Stability/' Rept. 66-C-192, 1966, General Electric Co. 6 Maddalon, D. V. and Henderson, A., Jr., Transition on Sharp Cones at Mach Numbers, AIAA Journal, Vol. 6, No. 3, March 1968, pp. 424-431. 7 Softley, E. J. and Graber, B. C., Experimental Observation of Transition of the Layer, AIAA Journal, Vol. 7, No. 2, Feb. 1969, pp. 257-263. 8 Deem, R. E. and Murphy, J. S., Flat Plate Layer Transition at Speeds, AIAA Paper 65-128, New York, 1965. 9 Sanator, R. J., DeCarlo, J. P., and Torrillo, D. T., Hypersonic Boundary-Layer Transition Data for a Cold-Wall Slender Cone, AIAA Journal, Vol. 3, No. 4, April 1965, pp. 758-760. 10 Rouse, H., A General Stability Index for Flow Near Plane Boundaries, Journal of the Aeronautical Sciences, Vol. 12, No. 4, Oct. 1945, pp. 429-431. 11 Rouse, H., Elementary Mechanics of Fluids, Wiley, New York, 1946, p. 172. 12 Cohen, N. B., Boundary Layer Similar Solutions and Correlation Equations for Laminar Heat-Transfer Distributions in Equilibrium Air at Velocities up to 41,000 Feet Per Second, TR R-118,1961, NASA. 13 van Driest, D. R. and Blumer, C. B., Boundary Layer Transition: Freestream Turbulence and Pressure Gradient Effects, AIAA Journal, Vol. 1, No. 6, June 1963, pp. 1303-1306. 14 Iverson, H. W. and Hsu, T.-T., A Local Reynolds Number to Predict Transition from Laminar to Turbulent Flow, Heat Transfer Thermodynamics and Education, McGraw-Hill, New York, pp. 207-212. BOUNDARY LAYER

Universal scaling laws for nose bluntness effects on hypersonic unsteady aerodynamics

The hypersonic aerodynamic characteristics of pointed bodies of revolution are relatively well understood and can be predicted theoretically, at least as long as the viscous effects are not large. No such satisfactory conditions exist for blunted bodies of revolution, especially not in regard to the bluntness induced effects on the vehicle dynamics. Embedded Newtonian flow concepts and hypersonic similitude are used to develop universal scaling laws that can predict the nose-bluntness induced effects on the hypersonic characteristics of slender bodies of revolution. The derived scaling laws are found to collapse the limited experimental data available. The laws permit one set of test data, or theoretically derived characteristics, to be extrapolated to predict the nose-bluntness induced effects for another configuration in the same geometric family, e.g., blunted cones and blunt cylinder-flare bodies. The derived scaling laws, when combined with existing pointed body theories, should provide the capability to predict the hypersonic unsteady aerodynamic characteristics of most blunter! slender bodies of revolution of current interest.

Effect of nose bluntness on hypersonic unsteady aerodynamics.

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Hypersonic Laminar Heat Transfer and Boundary Layer Transition on Blunted Cones

SummaryMeasurements have been made of laminar and transitional heat transfer rate distribution on a 15° semi-vertex angle, spherically blunted, cone at Mach numbers 8·6, 10·6 and 13·0. The laminar results are compared with theoretical predictions and good agreement is obtained with a modified form of the analysis due to Lees. Using a development of the correlation of pressure distributions previously obtained by the author, a new correlation of experimental and theoretical heat transfer results is suggested. The effect of nose bluntness on boundary layer transition has been observed both from flow visualisation and heat transfer results. It is suggested that the main factor causing nose bluntness to influence transition is the adverse pressure gradient which is induced.

A destabilizing effect of severe nose bluntness.

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Free-flight base pressure and heating measurements on sharp and blunt cones in a shock tunnel.

Nose bluntness and cone angle effects on base pressure and heating in laminar hypersonic flow regime, using free flight telemetry technique

Effect of nose bluntness on the hypersonic unsteady aerodynamics of an ablating re-entry body.

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