Local Heat Transfer and Recovery Temperatures on a Yawed Cylinder at a Mach Number of 4.15 and High Reynolds Numbers
Local Heat Transfer and Recovery Temperatures on a Yawed Cylinder at a Mach Number of 4.15 and High Reynolds Numbers

Author: Ivan E. Beckwith

Publisher:

Published: 1961

Total Pages: 36

ISBN-13:

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Design studies of hypersonic lifting vehicles have generally indicated that aerodynamic heating may be reduced by using highly swept configurations with blunted leading edges. For laminar boundary layers the effect of sweep angle A on the heat transfer at the leading edge is usually taken as cos A as shown by the data of Feller (ref. 1) who measured the average heat transfer on the front half of a swept cylinder. More recent data (refs. 2 and 3) have indicated that the effect of sweep may be more nearly cos3/2 Lambda which, at a sweep angle of 75 deg, would result in a 50-percent reduction of the heat transfer predicted by the cos A variation. The data and theory of reference 4 also indicate a cos3/2 lambda variation but the theories of references 5 and 6 indicate a variation somewhere between cos A and cos3/2 lambda for large stream Mach numbers. The data of reference 7, in contrast to the investigations just cited, showed large increases in average heat transfer to a circular leading edge with increasing A up to a lambda of about 40 deg. These increases in heat transfer were probably caused by transition to turbulent flow which apparently resulted primarily from the inherent instability of the three-dimensional boundary layer flow on a yawed cylinder. The leading-edge Reynolds numbers of reference 7 were considerably larger than the values in references 1 to 4 and were also larger than typical values for full-scale leading edges of hypersonic vehicles; hence, the main application of the high Reynolds number tests will probably be to bodies at angle of attack.

Convective Heat Transfer in Planetary Gases
Convective Heat Transfer in Planetary Gases

Author: Joseph G. Marvin

Publisher:

Published: 1965

Total Pages: 60

ISBN-13:

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Equilibrium convective heat transfer in several real gases was investigated. The gases considered were air, nitrogen, hydrogen, carbon dioxide, and argon. Solutions to the similar form of the boundary-layer equations were obtained for flight velocities to 30,000 ft/sec for a range of parameters sufficient to define the effects of pressure level, pressure gradient, boundary-layer-edge velocity, and wall temperature. Results are presented for stagnation-point heating and for the heating-rate distribution. For the range of parameters investigated the wall heat transfer depended on the transport properties near the wall and precise evaluation of properties in the high-energy portions of the boundary layer was not needed. A correlation of the solutions to the boundary-layer equations was obtained which depended only on the low temperature properties of the gases. This result can be used to evaluate the heat transfer in gases other than those considered. The largest stagnation-point heat transfer at a constant flight velocity was obtained for argon followed successively by carbon dioxide, air, nitrogen, and hydrogen. The blunt-body heating-rate distribution was found to depend mainly on the inviscid flow field. For each gas, correlation equations of boundary-layer thermodynamic and transport properties as a function of enthalpy are given for a wide range of pressures to a maximum enthalpy of 18,000 Btu/lb.

Physical and Computational Aspects of Convective Heat Transfer
Physical and Computational Aspects of Convective Heat Transfer

Author: T. Cebeci

Publisher: Springer Science & Business Media

Published: 2013-04-18

Total Pages: 497

ISBN-13: 366202411X

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This volume is concerned with the transport of thermal energy in flows of practical significance. The temperature distributions which result from convective heat transfer, in contrast to those associated with radiation heat transfer and conduction in solids, are related to velocity characteristics and we have included sufficient information of momentum transfer to make the book self-contained. This is readily achieved because of the close relation ship between the equations which represent conservation of momentum and energy: it is very desirable since convective heat transfer involves flows with large temperature differences, where the equations are coupled through an equation of state, as well as flows with small temperature differences where the energy equation is dependent on the momentum equation but the momentum equation is assumed independent of the energy equation. The equations which represent the conservation of scalar properties, including thermal energy, species concentration and particle number density can be identical in form and solutions obtained in terms of one dependent variable can represent those of another. Thus, although the discussion and arguments of this book are expressed in terms of heat transfer, they are relevant to problems of mass and particle transport. Care is required, however, in making use of these analogies since, for example, identical boundary conditions are not usually achieved in practice and mass transfer can involve more than one dependent variable.