Abstract
For determing pressure coefficients and Stanton numbers from the measured surface pressures and heat fluxes at a model surface, the dynamic pressure, mass flux and the total enthalpy of the free stream have to be known. Usually these values are determined by computing the wind tunnel nozzle flow. But a lot of uncertainties enter the computation which may lead to unreliable results. Therefore, a simple method was developed which yields the desired free stream conditions with high accuracy. This could be achieved by using mainly values which are measured within the test section. The method requires the measurement of the Pilot pressure, the stagnation point heat flux on a sphere and the static pressure of the free stream. For the static pressure an estimated value can also be used, because it has no large influence on the result. Some simple considerations show that the derived method is also valid for nonequilibrium free stream conditions. With the procedure presented the accuracy of the pressure coefficients and Stanton numbers could be increased significantly. Further, it improved the repeatability of these test results. This is very important for fundamental research, for the design of hypersonic vehicles as well as for CFD-validation with experimental data. The application of the method presented is not limited to short duration facilities, it can also be used for continuously working wind tunnels.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Esser B (1991) Die Zustandsgrössen im Stosswellenkanal als Ergebnisse eines exakten Riemannlösers. PhD Thesis, Shock Wave Laboratory RWTH Aachen
Fay JA, Riddell FR (1958) Theory of stagnation point heat transfer in dissociated air. J Aer Sci 25:73–85
Hayes WD, Probstein RF (1966) Hypersonic flow theory. Academic Press, New York London, p 248
Lobb RK (1964) Experimental measurement of shock detachment distance on spheres fired in air at hypervelocities. In: Nelson WC (ed) The high temperature aspects of hypersonic flow. Pergamon Press, Oxford London New York Paris, pp 519–527
Sawley ML, Wüthrich S (1991) Computation of viscous hypersonic flows using a coupled Euler/boundary layer method. In: Abgrall R, Désidéri JA, Glowinski R, Mollet M, Pénaux J (eds) Hypersonic flows for reentry problems. Proceedings of the INRIA-GAMNI/SMAI workshop on hypersonic flows for reentry problems, part II. Antibes, France, pp 535–557
Stalker RJ (1991) Some real gas shock tunnel experiments at Australian Universities. In: Abgrall R, Désidéri JA, Glowinski R, Mollet M, Périaux J (eds) Proceedings of the INRIA-GAMNI/SMAI workshop on hypersonic flows for reentry problems, part II. Antibes, France, pp 132–149
Stokes GG (1880) Mathematical and physical papers. Cambridge University Press 1:38–41
Truitt RW (1960) Fundamentals of aerodynamic heating. The Ronald Press Company, New York, pp 169–179
Van Dyke MD, Gordon HD (1959) Supersonic flow past a family of blunt axisymmetric bodies. NASA Technical Report R-1
Vetter M, Olivier H, Grönig H (1991) Flow over double ellipsoid and sphere experimental results. In: Abgrall R, Désidéri JA, Glowinski R, Mollet M, Périaux J (eds) Proceedings of the INRIA-GAMNI/SMAI workshop on hypersonic flows for reentry problems, part II. Antibes, France, pp 489–500
Author information
Authors and Affiliations
Additional information
This article was processed using Springer-Verlag TEX Shock Waves macro package 1.0 and the AMS fonts, developed by the American Mathematical Society.
Rights and permissions
About this article
Cite this article
Olivier, H. An improved method to determine free stream conditions in hypersonic facilities. Shock Waves 3, 129–139 (1993). https://doi.org/10.1007/BF02115892
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02115892