Reply To: Jos Koopman Conundrum
I have just realised that in my second to last paragraph I give 16 inlet diameters to achieve something around 75% effy on a diffuser, that should be 8. The design chart I work from (Miller, D.S. Fig.11.3) gives the length in radii, not diameters.
We are all fallible (me included as just demonstrated), However, if there are glaring contradictions in publicly quoted material, and considerable exaggeration in work by Porta it needs to be aired.
Porta gives comparisons of performance between various locomotives his Fig. 3 (His Rio Turbio 2-10-2 being top of the league, a Geisl 9F being about mid way) – does anybody know if the curves quoted are all TESTS or is he comparing test with calculation?