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).
Engine heat transfer analysis, focusing on heat absorbed by oil and cooling water.
| Identifier | ExFiles\Box 131\1\ scan0127 | |
| Date | 13th February 1934 | |
| -2- The figure for the heat picked up by the oil from the Piston Crowns we assumed as 30% of the total heat to the oil: this assumption is based on tests carried out on Peregrine, FX1 and other units. We hope to have the chance of determining this figure accurately at a later date but it will be necessary to have a car on the dynamometer test to do this. The quantity of heat given to the oil on an engine with standard Balance Weights and standard Connecting Rods with white metal bearings may vary somewhat due to the fact that the oil flow may be different and the fact of balancing the Crankshaft has a definite effect on the heat given to the oil. This will be mentioned later in this report. (5) HEAT TO COOLING WATER. The total heat to the cooling water was determined by measuring the Inlet and Outlet temperatures and the flow of water. A certain amount of this heat is due to Piston friction and by motoring a car over on the dynamometer with cylinders not firing we found how much heat was given to the water by this means. The initial fuel energy we found to be 18,300 B.T.U's/minute. This figure was arrived at by taking the Lower Calorific Value of D.T.D.224 (the fuel used) as 141,200 B.T.U's/gallon, and of this amount 4,220 B.T.U's/minute or 23.1% was available as Effective Motor Power or B.H.P. The total loss to Friction and Pumping we estimated to be 1540 B.T.U's/minute or 8.41%: this of course takes in the heat given to the oil by Friction of Bearings etc. and heat given to water by Piston Friction. The heat accounted for by Bearing Friction etc. amounts to 147.1 B.T.U's/minute, which again can be separated into two parts, namely - (1) Actual heat given to oil by bearings. (2) Heat given to oil by pump and gears etc. | ||