International Journal of Mechanical Sciences 42 (2000) 185 } 198 Analysis and modeling of a two-phase jet pump of a thermal management system for aerospace applications S.A. Sherif *, W.E. Lear , J.M. Steadham, P.L. Hunt , J.B. Holladay   Department of Mechanical Engineering, University of Florida, 228 MEB, P.O. Box 116300, Gainesville, FL 32611-6300, USA  Thermal and Life Support Division, NASA-Marshall Space Flight Center, Building 4610, MSFC, AL 35812, USA Received 20 April 1998; received in revised form 30 November 1998; accepted 30 November 1998 Abstract Jet pumps are devices capable of pumping #uids to a higher pressure by inducing the motion of a secondary #uid employing a high-speed primary #uid. The main components of a jet pump are a primary nozzle, secondary #uid injectors, a mixing chamber, a throat, and a di!user. The work described in this paper models the #ow of a two-phase primary #uid inducing a secondary liquid (saturated or subcooled) injected into the jet pump mixing chamber. The model is capable of accounting for phase transformations due to compression, expansion, and mixing. The model is also capable of incorporating the e!ects of the temper- ature and pressure dependency in the analysis. The approach adopted utilizes an isentropic constant- pressure mixing in the mixing chamber and at times employs iterative techniques to determine the #ow conditions in the di!erent parts of the jet pump.  1999 Elsevier Science Ltd. All rights reserved. Keywords: Jet pumps; Ejectors; Two-phase #ow; Aerospace thermal management Nomenclature Latin symbols A cross-sectional area, m a speed of sound, m/s h speci"c enthalpy, kJ/kg M Mach number, dimensionless m R mass #ow rate, kg/s * Corresponding author. Tel.: # 1 352 392 7821; fax: # 1 352 392 1071; E-mail: sasherif@cimar.me.u#.edu 0020-7403/00/$ - see front matter  1999 Elsevier Science Ltd. All rights reserved. PII: S 0 0 2 0 - 7 4 0 3 ( 9 8 ) 0 0 1 2 3 - 4