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).
Hydraulic resistance and choking issues in F2B, S.S., and V series radiators.
| Identifier | ExFiles\Box 24\5\ Scan205 | |
| Date | 30th August 1929 | |
| X766 To Da.{Bernard Day - Chassis Design} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Ev.{Ivan Evernden - coachwork} E.{Mr Elliott - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/MJ30.8.29. COOLING SYSTEMS. X7250 X766. With reference to Da{Bernard Day - Chassis Design}2/M24.8.29. RADIATORS CHOKING UP. We do not think that there is any mystery in the fact that the hydraulic resistance of the F2B series and S.S. radiators is greater than that of V series. You have balanced them by shewing that with smaller dia. tubes there will be more water passages in the top row. However, there will be exactly the same percentage increase in the number of passages to be traversed in the depth of the radiator. Therefore, we cannot see that there will be any difference in the restriction of two radiators of the same dimensions only if one is fitted with 6/7 m.m. tubes and the other 7/8 mm. tubes. Hence we think that F2B series radiators (neglecting the top tank over-lapping) would have the same hydraulic resistance as V series radiator were its water passages not 11% shorter and its depth of matrix not 8% greater. In the case of the original S.S. the tubes were 17½% shorter and the depth 15.75% greater, which has now been, we believe, adequately compensated for by the 50% increase in gap size which experiments show has brought us back to a point considerably better than F2B series. CHOKING UP. While the hydraulic restriction of the radiator | ||