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 performance tests comparing the effects of high intake air temperature on power and economy.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan255 | |
| Date | 26th June 1926 guessed | |
| contd :- -5- temperature is high, such as would be encountered in a hot climate. We know that when the distribution is reasonable the power will decrease with the increase of air temperature - due to the loss of volumetric efficiency - and the following test, which took the same form as the previous one, was taken with normal hot spot heating and intake air at 80°C to determine the effect both on power and economy. The results of this test however, are interpreted in a different way. The specific consumption - pts/HP/HR - is plotted against the B.M.E.P. and by this means we are able to compare the power and economy of the system under normal and high temperature conditions. Curves are given on the next page and the results of the previous experiment are inserted for comparison. The noticeable thing from the curve is that with high air temperature the range of stable running is considerably increased. The maximum M.E.P. is reduced by [strikethrough]the-temperature-giving the-maximum-h.p. by[/strikethrough] 5 lbs/sq.in. but the specific consumption giving the maximum M.E.P. is approximately the same in each case at .7 pts/HP/Hr. or even very slightly less in the case of the high temperature. The high temperature curve is also flatter at the point of maximum torque which means that further economy can be obtained without any appreciable further reduction in power. The maximum economy which can be obtained - but at the expense of a reduction in M.E.P. - is the same giving .59 pts/HP/Hr. The curve of heat supply by hot air only lies well contd :- | ||