Asimple brayton cycle is working under the following conditions: working fluid: air pressure ratio: 8 minimum and maximum temperatures of the cycle: 290k and 1500 k, respectively an engineer decides to double the pressure ratio and keep the maximum and minimum temperatures constant. evaluate the change in specific net work and thermal efficiency of the cycle as result of that modification. assume variable specific heat for the air.

Steel balls 12 mm in diameter are annealed by heating to 1150 k and then slowly cooled to 400 k in an air att 325 k and h -20 w/m2 k. assume the properties of the steel to be k- 40 w/m k,p 7800 kg/m3, and cp 600 j/kg k. a. determine whether lumped system method can be used to analyze this problem and if so why" b. determine the time required for the cooling process. c. determine the total amount of heat lost from each ball to the ambient air