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).
Experiments to improve mixture distribution in a supercharged Kestrel engine at high altitudes.
| Identifier | ExFiles\Box 179\2\ img180 | |
| Date | 1st January 1932 | |
| ORIGINAL R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Aln. c. to Sg.{Arthur F. Sidgreaves - MD} Mor. c. to RS.{Sir Henry Royce's Secretary} E.{Mr Elliott - Chief Engineer} c. to RY. Hs{Lord Ernest Hives - Chair}/Aln.S/MA.22. 1. 32. X4550 X3933 SUPERCHARGED KESTREL - MIXTURE DISTRIBUTION. We have been running a Kestrel blower unit on a rig, feeding the carburetter with water, with a view to observing the flow of liquid from the blower elbow or induction pipe connecting sleeve attached thereto and of endeavouring to improve it. The water represents petrol which fails to vaporise when low temperatures are encountered at high altitudes. We confined the tendency found on similar tests reported in HA/ACL.1/MJ.25.4.30., of the spray to concentrate, at full speed, near the top of the pipe and to whirl in a right hand direction, while at the bottom the mixture is very weak. Fitting the standard re-distributor having the discharge stand-pipe in the centre reduced these effects to some extent but, did not alter the general tendency. It was found that a further improvement was effected if the redistributor was rotated until the stand-pipe was in the path of the densest portion of the spray. These effects of the redistributor were very little altered if the discharge hole in the stand-pipe, was plugged with a cork. Hence we concluded that the redistributor does not act selectively as between liquid and gas but that these will emerge in the same proportion as they enter the annular scoop and therefore that they require an easy path preserving full cross section as they flow. It appeared that the simplest way of transferring the rich mixture at the top of the pipe to the weak portion at the bottom would be by means of a tube slightly smaller than the induction pipe connecting sleeve and mounted inside it with a tilt as shown in Fig. 1 on attached sketch. This actually gave a mixture rich at the bottom, and by carful adjustment could be made to give a fairly even distribution all round the periphery of the pipe. From this was schemed the arrangement shown in FIG. 2 with the idea of transferring the spray to the centre of the pipe rather than moving it to another part of the wall. It comprises two tubes (slightly distorted) with the inner | ||