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Sorry, if it makes you uncomfortable. I was just presenting.The calculations and science involved in this make my head hurt, eyes pop out and ears bleed. If it was 55% of the size in some way it must have been more efficient, so how do you define efficiency. Weight is one thing normally science uses mass and density. The density of copper may be 3 times that of aluminium, but copper is a much better conductor of heat than aluminium. If you can make a higher pressure system it will have less water and be smaller. The water you put in a cooling system has far more mass or weight than the heat exchange matrix in the radiator.
I don't think so.Not sure if there's an analogue here with the transition from fire tube boilers to water tube boilers?
Heat exchanger efficiency is very well defined in my branch of mechanical engineering. I recall running tests on F-4 and F-106 environmental control system heat exchangers well into the nighttime hours to determine if the repair procedures employed decreased their capabilities..Pedantically, "efficiency" doesn't apply to heat exchangers, of which radiators -- which don't work by radiation -- are an example. as heat exchangers do no work.
Pedantically, "efficiency" is energy in divided by work out. Heat exchangers don't do work, so, pedantically, "efficiency" is not correct. This is not a hill I'm going to die on, although my engineering thermo and HX instructors would yell at me for using "efficiency."Heat exchanger efficiency is very well defined in my branch of mechanical engineering. I recall running tests on F-4 and F-106 environmental control system heat exchangers well into the nighttime hours to determine if the repair procedures employed decreased their capabilities..
Fin-plate heat exchangers are known to be significantly more efficient than tube-shell heat exchangers. That increased efficiency means that you need a smaller heat exchanger for the job at hand. Shell-tube heat exhangers are easier to construct and to repair but fin-plates (like a car radiator) are more efficient. I recall one company telling us that they could use the techniques employed to repair F-106 shell-tube heat exchangers to replace the fin-plate types used on other fighters and that they had done so for Boeing 727 units. But airliners have a lot more margin than jet fighters and we told them No.
The greatest heat exhanger triumph of WW2 was the Aftercooler for the two stage Merlins. Without that compact lightweight unit the Spitfire would have been virtually out of business by 1943 and the P-51 never developed into a long range escort fighter. An air to air aftercooler would never have worked. The fact that Stanley Hooker recognized this and did not instead pursue his own expertise at cajoling air to behave better shows just how brilliant he was.
View attachment 787828
Those numbers don't sound right...You are correct. For heat exchangers, effectiveness is used to measure performance.
From "Fundamentals of Heat Exchanger Design", Shah et al
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subscripts: h = hot fluid, c = cold fluid, i = inlet, o = outlet.
For intercoolers, they generally talk about efficiency as a measure of how much temperature was decreased by the intercooler compared to the temperature rise caused by compression. For the Merlin, the efficiency was about 40% (Lovesey's Merlin paper). The inlet temp rise at FS at max revs was 205°C (Lovesey's Merlin paper) and temp at the intercooler exit was 100°C (Hooker's autobiography).
Those numbers don't sound right...
(205-100)/.4 = 262.5, as output temperature can't be more than 205C, that says input had to be -57.5C And there is no way the "radiator" could be cooling the glycol water to that temperature.
I don't think so.
Fire tube boilers had hot gases flowing though the tubes in the 'water tank/boiler'.
Water tube boilers had a collection of water/steam filled tubes suspended in the 'fire' or pathways the hot gases took from the firebox/burners.
There are some advantages to each type. The number of railroad locomotives that used water tube boilers can be counted on one hand.