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).
Analysis of engine tests varying oil discharge to study its effects on heat dissipation from bearings and pistons.
| Identifier | ExFiles\Box 69\4\ scan0356 | |
| Date | 17th October 1927 guessed | |
| contd :- -3- the quantity of oil thrown from the bearings would influence the amount of heat picked up from this source. We therefore varied the oil discharge from the bearings by means of an adjustable pressure release valve which could be operated while the engine was running. The appended table is an average of the results obtained. It will be seen that decreasing the oil discharge from 37 lbs/min. to 16 lbs/min. the heat it was necessary to dissipate to the cooler in order to maintain an inlet temp. of 66°C was reduced from 637 B.T.U's/min. to 512 B.T.U's/min. To give these flows the oil pressure was reduced from 79 lbs/sq.in. to 25 lbs/sq.in. As would be expected with the small rate of oil circulation the temp. of oil issuing from the big end bearings was higher than with the greater flow. With the small circulation the temp. rose to 96°C and was 88°C with the larger flow. These tests prove that a certain amount of heat which the oil has to dissipate is picked up from the pistons. Under the conditions of our tests and the oil circulation employed we estimated the amount due to this source to be 29%. Furthermore the larger the oil circulation through the bearings the greater the amount of heat picked up, and it is reasonable to suppose that this is due to the greater amount of oil thrown on to the pistons. The oil circulation through the bearings, which was the factor varied during these tests, must not be confused with the total oil circulated by the pump which xxxxx remained constant for all the tests. It has been suggested that the high rate contd:- | ||