A round rotor generator delivers steady state power Pe = 0.5 p. u. to an infinite bus through a transmission line with Xl = 0.4 p. u. |Eg| = 1.8 p. u., V[infinity] = 1.00 p. u., H = 5 sec, Xd = Xq = 1.0 p. u. Neglect resistances. The generator experiences a bolted three phase fault at its terminals. Circuit breakers open to clear the fault, then successfully reclose six cycles (0.1 sec) later. Find the maximum value of the generator rotor angle δ. Neglect damping. Sketch the areas.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Give heat transfer applications for the following, (i) gas turbines (propulsion) ) gas turbines (power generation). (iii) steam turbines. (iv) combined heat and power (chp). (v) automotive engines

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way