The purposes of this book are to provide insight and to draw attention
to problems peculiar to heat transfer at low temperatures. This does not
imply that the theories of classical heat transfer fail at low
temperatures, but rather that many of the approximations employed in
standard solutions techniques are not valid in this regime. Physical
properties, for example, have more pronounced variations at low
temperatures and cannot, as is conventionally done, be held constant.
Fluids readily become mixtures of two or more phases and their analysis
is different from that for a single-phase fluid. These and other
problems which occur more frequently at low temperatures than at
standard conditions are discussed in this book. Although the title
specifies heat transfer, the book also contains a very comprehensive
chapter on two-phase fluid flow and a partial chapter on the flow of
fluids in the thermodynamically critical state. Emphasis is placed on
those flow phenomena that occur at low temperatures. Flow analyses are,
of course, a prerequisite to forced-convection heat transfer analyses,
and thus these chapters add continuity to the text. The book is
primarily written for the design engineer, but does broach many topics
which should prove interesting to the researcher. For the student and
teacher the book will serve as a useful reference and possibly as a text
for a special topics course in heat transfer.