A preliminary report of results obtained concerning radiation intensities measured with single Geiger tubes carried by Explorer I and III is presented. Resonable cosmic-ray counting rates were obtained for altitudes below about 1000 km. A plot of omnidirectional intensity vs. height in the vicinity of California for the first two weeks in February was obtained, This curve, extrapolated down to altitudes previously reached by rockets, agrees with earlier data, At altitudes greater than about 1100 km, very high counting rates were obtained. (W.D.M,)
The author studied engineering _ science at Harvard University ^ t f t f f lH^ where he received an A.B. in 1946 J ^ B I ^ ^ J L and a Ph.D. in 1949. His thesis flB V | was on an experimental measureI p l l llfcll ment of vibrational relaxation ISfl l ^iTW times in gases. In 1950 he joined ^ ' * 8 U H Wr the shock wave laboratory of the ^ n H E ' ^^i^mi^tJt Physics Department at Princeton ^SK^SJ^L I I L Z ^ ^ 1 ^ University where he continued his l l l l ^ j l H H k ^ research on physical problems in ' l l L ^ ^ • I H H B L gas dynamics. In 1951 he was ^ B « . / | ^ ^ H | | | H u appointed assistant professor of physics; later, associate professor. The subjects on which he has worked extensively include transonic flow, thermal boundary layers, shock structure, chemical kinetics, diffraction of blast waves, and supersonic flow. As one of the editors of the Journal of Fluid Mechanics, he has an intimate and up-to-date knowledge of the problem on which he writes. Dr. Griffith is currently manager of the Flight Sciences Division in the Missile Systems Division of Lockheed Aircraft Corp.
Turbulent heat transfer rates on the aft portion and on the blunt base of a hemisphere cylinder were measured in the 2-7/8 x 2-7/8 GALCIT shock tube over a range of shock Mach numbers between 3. 25 and 5. 1 and initial pressures between 3 and 17 em. Hg. The local Reynolds numbers on the cylindrical afterbody varied between 3.5 x 10^4 and 3.0 x 10^5 per em. A side support was used for the model in order to eliminate the disturbing effect of a rear sting support. The measured turbulent heat transfer rates on the cylindrical portion agreed very well with previous flat plate measurements for small temperature differences, although the ratio of stagnation to surface enthalpy varied between 3 to 8 in the present tests. Only a slight effect of this large variation in h_s/h_w was detected in this range of local Mach numbers, i.e., 1.25 < M_e < 1.5. The measured heat transfer rate on the base indicated that at the center of the base the heat transfer rate is comparable to that on the surface just ahead of the base, while the heat transfer rate falls off to 1/2 to 1/3 of this value towards the rim of the base. This unexpected distribution of heat transfer rate over the base, and particularly the high value at the center, shows the necessity for a careful study of wake phenomena.
