An analysis is presented of the fluid flow and heat transfer characteristics of a highly rarefied gas passing through a tapered tube or conical nozzle. The rate of mass throughflow has been determined as a function of the pressures and temperatures of the system and of the tube dimensions. It is found that, at moderate and large angles of taper, the mass throughflow is affected little by increases in tube length, except for short tubes. At small taper angles, the mass throughflow is more sensitive to tube length. The energy transport analysis includes simultaneous convection and radiation. Numerical results have been found for the adiabatic wall temperature. It is found that, for surfaces that can be approximated realistically as diffuse emitters and reflectors of thermal radiation, the results differ little from those for pure radiation.
Bibliographical noteFunding Information:
Received by IAS November 21, 1962; revision received April 1,1963. The authors gratefully acknowledge the cooperation of the Numerical Analysis Center of the University of Minnesota. Their research was supported in part by the National Science Foundation, Grant G-10117. * Professor of Mechanical Engineering, Heat Transfer Laboratory, Department of Mechanical Engineering. t Research Assistant, Heat Transfer Laboratory, Department of Mechanical Engineering.