Bents Space Creative Corner Power

Drag on rim x travel of rim in feet ; that is to say: ( w - s ) x 2 phi n. So that the horse-power of the engine is: 2 phi r n (w - s ) / 33000. The force (w - s) multiplied by radius r at which it is overcome is what we have called the torque of the engine, so we can write the above formula: B.H.P. = 2 phi t n /33000. A long shaft, like the propellor shaft of a steamship, is twisted slightly by the effort it transmits and this twist, indicated by a special optical appliance attached to the revolving shaft, affords a measure of the torque t for inserting in the above B.H.P. .Step 1. During a brake test on a steam-engine having a flywheel of diameter 5 ft., the speed in revolutions per minute was 240 and the weight on the brake rope was 250 lb. The spring-balance reading was 30 lb. What torque did the engine exert, and what brake horse-power did it devolop? The torque = ( 250 - 30 ) x 2 1/2 = 550 ft.-lb. B.H.P = 2 PHI X 550 X 240 / 33000 = 25.1. Step 2. What torque or turning effort is exerted by an omnibus engine that devolops 110 B.H.P. at 2500 r.p.m. By rearranging the formula above for B.H.P. we get: t = 33000 x B.H.P. / 2 Phi n and =  33000 x 110 / 6.284 x 2500 = 231 lb.-ft. Notice here that `torque`is measured in the same sort of units as work, but to distinguish it from work we give our result in pounds-feet rather than in foot-pounds. Step 3. Measuring B.H.P at 2500 r.p.m.? 2500/ 25.1 = 99.6015936254 / 250 / 25.1 = 9.96015936254 = 11 x 10 = 110 B.H.P.= 2500/110 = 22.72727272727 X 11 = 250 / 25.1 = 9.9601593625 X 25.1 = 2500. 231 lb-ft. x 1.488 = 343.728 kg.metres/0.1383 = 248537960954 Foot Pounds x 3.766 x 10-7 = 0.00093599396 Kilowatt__Hours x 3415 = 3.1964193734 British Thermal Units/ 56.92 = 0.05615634879 Kilowatts x 1.341 = 0.07530566372 Horse Power x 33000 = 2485.08690276 Foot Pounds. 6.2832 X 231 X 2500 = 3628548/ 33000 = 110 B.H.P. Step 4. Brake H.P. Motors with Efficiencies and Power Factor. Three phase: b.h.p = E. = Voltage 130.4196 x  I  current in ampers x  pf. 90.1019043346 Power Factor and  Percentage efficiency of motor x 92 x 1.732 = 25.1. Efficiency = Rews per Min 1450 = 92 with H.P 490 at 50 degrees Celsius Rise and Power Factor with Rews per Min. 1450 = 90.1019043346.

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B.b.h.p B.H.P. = 2500 / 110