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).
Under bonnet temperatures and proposing solutions related to airflow and deflection plates.
| Identifier | ExFiles\Box 131\4\ scan0246 | |
| Date | 31th May 1937 | |
| 1113 To Hs.{Lord Ernest Hives - Chair} c. to Rm.{William Robotham - Chief Engineer} Kingsbury, May 31st, 1937. UNDER BONNET TEMPERATURES. A test recently carried out on 35-EX removing the side engine guards to try and get rid of the hot air under the bonnet is in my opinion entirely wrong, and as was the case with 35-EX the engine became smothered with water and dirt. The principles of air flow had not been taken into consideration. To get air from under the bonnet there must be a suction effect, and the streamline under the chassis must make this possible. In the case of Phantom III the front pan of the independant springing causes an upward swirl of air towards the rear of the engine and instead of pulling air out of the bonnet keeps it there under pressure. To overcome this condition deflection plates should be placed at either side of the engine to divert the air stream downwards after leaving the front pan. Experiments on these lines would considerably help the efficiency of the radiator and floor board temperatures. Models in a wind tunnel would be the correct way of quickly dealing with it. Rm{William Robotham - Chief Engineer}/G.W.Hancock. | ||