Heat transfer in the cavity of a turbo pump is a conjugate problem that encompasses forced convection in the annular exit passage, conduction through the dumbbell-shaped hub wall, mixed convection in the cavity, and the conduction through the rotating disk. The numerical solution of this problem for a wide range of turbulent rotational Reynolds numbers (ReΩ) is obtained. The procedure, based on a finite volume code, has been validated against available experimental data for similar but geometrically simpler problems. The velocity, stream function, and temperature contours are presented to explain the complex flow behavior in the physical model. The average Nusselt number variations are correlated in the form: (Formula presented). © 2004 Taylor & Francis Group, LLC.