Showing papers by "Richard J Goldstein published in 1978"

Porous surface solar energy receiver

Abstract: A porous surface receiver and concentrator of reflected solar radiation. The receiver is part of a moderately or strongly concentrating solar collector such as a solar power tower system. In the latter, radiation is reflected by a plurality of heliostats disposed about the tower on which the receiver is mounted. The solar radiation is reflected onto the central heat transfer receiver where the energy is transferred to a working fluid. Atmospheric air is used as the working fluid. The air is drawn through the porous matrix of the receiver surface and is heated to a high temperature in the range of 500° to 1500° C. with only a moderate pressure drop. The radiant heat flux input may be hundreds of times the incoming solar flux to the earth surface. The hot air can be used in a thermal storage system, or directly in a heat exchanger, or the like.

Flow and temperature fields following injection of a jet normal to a cross stream.

Abstract: The interaction of a jet entering into a freestream normal to the main flow direction has been studied with particular attention directed to visualization of the large-scale flow interactions and to measurement of the film-cooling performance. Large eddies are apparent downstream of the entering jet even at moderate blowing rate (defined as the ratio of the mass velocity of the jet to the mass velocity of the freestream). At higher blowing rate, there is only intermittent contact between the mass from the jet and the downstream wall. The film cooling downstream from a single normal jet yields a lower centerline effectiveness compared to an inclined jet through a greater lateral spreading. The greater spreading provides a more uniform effectiveness across the span of the downstream wall, in particular at large blowing rate.