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).
Letter from Harrison Radiator Corporation discussing the relative cooling performance and specifications of various radiator cores.
| Identifier | ExFiles\Box 149a\3\ scan0161 | |
| Date | 9th April 1936 | |
| X1278 STEADMAN HARRISON RADIATOR CORPORATION LOCKPORT, NEW YORK April 9, 1936 Hilsen - As/SPO Messrs. Rolls-Royce Limited Derby, Derbyshire, England Attention: Mr. C. S. Steadman Dear Mr. Steadman: Ref: Hs{Lord Ernest Hives - Chair}/Std.5/KW The curves on relative cooling on the Mark V and Mark VI blocks, as well as one of the Harrison Radiator blocks and a Gallay core, enclosed in your letter of March 9th have been gone over and you may be interested in knowing that the figures of the Harrison block approximate the figures obtained over here. Of course, we run our speed up to the neighborhood of 100 MPH but so far as the curve has been run, it follows fairly closely the Harrison figures. A schematic drawing is enclosed which will straighten out the matter of cell size, such as 20 x 55, 18 x 62, 35 x 45, etc.,etc. The first figure is the pitch of the fins and the second figure is the center to center distance of the water tubes. The air gap as explained in a previous letter, shows the space from the top of the louvre of one fin to the top of the louvre of an adjacent fin. Examination of the centers through which the air passes, or over which the air passes, as it passes through the core, will disclose what is meant by louvres. They are the small slits within this material deformed at the edge of the slit. The explanation of the contradictory statement made in my letter of January 6th stating that the poorest performing core is the best performer on the automobile, is made by referring to the two marked up charts which are also enclosed. One shows a constant dissipation of 1600 BTU per minute per square foot and the varying air velocities to obtain this dissipation with cores having different heights of air gaps. The second chart shows a constant air flow with a variation in dissipation, again with the cores having different heights of air gaps. Thus it will be seen that on the first chart mentioned, if the maximum velocity which can be obtained is in the neighborhood of 2,080 CFM, the .060 gap to equal the dissipation requires 2,540 CFM. Again, if the design of the machine is so arranged that the maximum amount of air which can pass through the grille to the core or from the back of the core out, under the hood or through the hood louvres, etc., etc., is 2250 CFM, the most satisfactory core to use under these conditions is the .020 gap which dissipates 1625 BTU as compared to 1460 BTU with the .060 gap. HEAT TRANSFER PRODUCTS AVIATION AUTOMOTIVE MARINE INDUSTRIAL RADIATORS SHUTTERS OIL TEMPERATURE REGULATORS CAR HEATERS THERMOSTATS HEAT EXCHANGERS | ||