From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Brief list and summary of tests comparing heat dissipation and air speed in various radiator matrices.
| Identifier | ExFiles\Box 87\1\ scan0169 | |
| Date | 6th November 1935 | |
| -4- Hs{Lord Ernest Hives - Chair}/Std.14/KW. 6.11.35. Below we give a brief list of the tests shown on attached sheets :- (1) Sheet 1 shows a comparison between the American Bentley matrix and the Mark VI Bentley matrix, carried out by Marstons. This shows approximately 8% (mean figure) gain in heat dissipation with the A.H.V. matrix (American Harrison Vee - bonded) as against 6.5% measured by us on their rig (one car speed only - 30 m.p.h.) and 5.5% (85 m.p.h. car speed only) measured by us at Brooklands. (2) Sheet 2 shows a comparison between the Mark V and Mark VI Bentley matrices, different frontal area blocks being used for the tests and results being corrected to same area. This shows a gain of 18% (mean) with the Mark VI block, as against 9% measured by us at Brooklands. (3) Sheet 3 shows the variation of heat dissipation with matrix depth at constant car speed, tests being repeated at various car speeds - this for the Marston Mark V type of block. (4) Sheet 4 shows the variation of heat dissipation with car speed for different depth matrices (all Mark V). (5) Sheet 5 shows the variation of air speed through matrix with the car speed, for different depths of matrix. This was obtained by equating the heat from the water to the heat to the air, and knowing the air temperature rise, specific heat and density, calculating the air velocity on the basis that the free area for the air through the matrix equals the frontal area - actually the free area will be less than this (say kA where k is approximately .6 or .7), and the velocity higher in the ratio of 1/k.{Mr Kilner} The results in the cases of the 52 m.m. and 65 m.m. Mark V matrices are consist, but that of the 84 m.m. matrix seems to be definitely wrong, since it gives a higher air speed than either the 52 m.m. or 65 m.m. matrices. | ||