EXPERIMENTAL MODELING OF CENTRAL AXIS AND JET-RING TURBINE DISK COOLING

The test facility, experimental methods, and summary results are prese nted from a study modeling turbine diskcooling with multiple impinging jets, such as employed on the Space Shuttle Main Engine oxygen turbop ump. The study was designed to provide a comparison of detailed local convection heat transfer information obtained with a single center-sup ply of disk coolant, as opposed to the present night configuration whe re disk coolant is supplied through an array of 19 radially outboard j ets. Specially constructed turbine disk models were used in a program to evaluate possible benefits and tradeoffs of employing an alternate disk cooling scheme. The study involved the design, construction, and testing of two full-scale rotating model disks, one plane and smooth f or baseline testing and the second contoured to the present flight con figuration, together with the corresponding plane and contoured stator s. Local heat transfer rates are determined from the color display of encapsulated liquid crystals coated on the disk in conjunction with us e of a computer vision system. The test program was composed of a wide variety of disk speeds, flow rates, and geometrical configurations, i ncluding testing for the effects of bolt heads and hot gas entrainment into the disk cavity.