Calculations for the heat dissipation and critical air temperature of a Spectre matrix.
| Identifier | ExFiles\Box 87\1\ scan0171 | |
| Date | 6th November 1935 | |
| (Appendix - Sheet 1) Calculations for Spectre(Codename for Phantom III) Matrix. From test bed figures, heat to be dissipated at 85 m.p.h. full throttle = 8100 B.T.U's/min. From test figures, at 85 m.p.h. dissipation of Mark V 54 m.m. matrix block (taking untinned block figures as most reliable)= 66.5 B.T.U's/min/°C. diff. temp. between air and water inlet temps. for a 2 sq.' block. If H = heat dissipated/min. & Δt = °C. temp. difference between inlet air and water A = frontal area of Spectre(Codename for Phantom III) matrix in sq.'. ∴ H / Δt = 66.5A / 2 H = 8100 A = 602 / 144 ∴ Δt = (2 x 8100 x 144) / (66.5 x 602) = 58.5°C. ∴ In limiting case where water inlet = 100°C. air inlet = critical air temp. = 100 - 58.5 = 41.5°C. (Note: Critical air temp. = "air temp. to boil"). | ||
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).