A preliminary investigation has been made of the effects of heat transfer on boundary-layer transition on a body of revolution at a Mach number of 1.61 and over a Reynolds number range of 7,000,000 to 20,000,000, based on body length. The body had a parabolic-arc profile, blunt-base, and a fineness ratio of 12.2 (NACA RM-10). The results indicated that, by cooling the model an average of about 50 degrees F, the Reynolds number for which laminar boundary-layer flow could be maintained over the entire length of the body was increased from the value of 11,500,000 without cooling to over 20,000,000, the limit of the present tests. Heatig the model an average of about 12 degrees F on the other hand decreased the transition Reynolds number from 11,500,000 to about 8,000,000. These effects of heat transfer on transition were considerably larger than previously found in similar investigations in other wind tunnels. It appears that, if the boundary-layer transition Reynolds number for zero heat transfer is large, as in the present experiments, then the sensitivity of transition to heating or cooling is high; if the zero-heat-transfer transition Reynolds number is low, then transition is relatively insensitive to heat-transfer effects.

This book is a self-contained text for those students and readers interested in learning hypersonic flow and high-temperature gas dynamics. It assumes no prior familiarity with either subject on the part of the reader. If you have never studied hypersonic and/or high-temperature gas dynamics before, and if you have never worked extensively in the area, then this book is for you. On the other hand, if you have worked and/or are working in these areas, and you want a cohesive presentation of the fundamentals, a development of important theory and techniques, a discussion of the salient results with emphasis on the physical aspects, and a presentation of modern thinking in these areas, then this book is also for you. In other words, this book is designed for two roles: 1) as an effective classroom text that can be used with ease by the instructor, and understood with ease by the student; and 2) as a viable, professional working tool for engineers, scientists, and managers who have any contact in their jobs with hypersonic and/or high-temperature flow.

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.