List of top Fluid Mechanics and Thermal Sciences Questions on Power Engineering asked in GATE ME

Consider an air-standard Brayton cycle with adiabatic compressor and turbine, and a regenerator, as shown in the figure. Air enters the compressor at 100 kPa and 300 K and exits the compressor at 600 kPa and 550 K. The air exits the combustion chamber at 1250 K and exits the adiabatic turbine at 100 kPa and 800 K. The exhaust air from the turbine is used to preheat the air in the regenerator. The exhaust air exits the regenerator (state 6) at 600 K. There is no pressure drop across the regenerator and the combustion chamber. Also, there is no heat loss from the regenerator to the surroundings. The ratio of specific heats at constant pressure and volume is \(\frac{C_p}{C_v} = 1.4\). The thermal efficiency of the cycle is _____% (answer in integer).

A cylindrical billet of diameter 100 mm and length 100 mm is directly extruded into an L-section. The extrusion pressure is given by \[ p = K_s\, \sigma_m \left[0.8 + 1.5\ln(r) + \frac{2l}{d_0}\right] \] where \( \sigma_m = 50\ \text{MPa} \), \( K_s = 1.05 \), \( d_0 = 100\ \text{mm} \). Find the maximum force at the start of extrusion (in kN).

A project consists of five activities (A, B, C, D, E). Each activity duration follows beta distribution. Three-time estimates are given and expected completion time is __________ weeks (in integer).