Showing papers by "Peter D. Richardson published in 1968"

The generation of scour marks near obstacles

Abstract: Local depressions in a sediment bed, caused by local nonuniformity of the flow, are often found in the vicinity of obstacles lying on or embedded in the sediment. It is concluded that current crescent scour marks can be explained as effects of the stretching and accumulation of the vorticity in the flow approaching an obstacle, the fluid-mechanical aspects of vorticity transport being described in some detail. The observed differences between scour-remnant ridges and scour-deposit ridges may be explained in terms of differences in the flow configuration geometry. Sediment transport is a functional with respect to some of the hydraulic variables--that is to say, the transport depends not only on the range of values of fluid velocity, for example, but also upon the sequence in which the values in the range are attained. This aspect of transport phenomena is emphasized and it is suggested that experiments should be performed to determine the sensitivity of the functionals to the flow functions.

Transient heat transfer in human skin

Abstract: Experiments are discussed which assess the influence of sudden, localized changes of thermal load on the conductance of human skin; the conductance is expected to change due to the thermal regulatory role of skin. The changes are produced by placing local areas of skin in contact with passive probes which are pre-heated or pre-cooled. It is found that the change in conductance is effectively independent of the surface temperature (and of the surface heat flux) to which the skin is exposed at the beginning of each test, for elapsed times exceeding one minute.

Surface temperatures of the Galilean satellites of Jupiter.

Abstract: Surface temperatures for Galilean satellites of Jupiter calculated through corresponding lunations, assuming synchronous orbits with respect to Jupiter