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A piston-cylinder device contains 5 kg of saturated water vapor at 3 MPa. The surrounding temperature is at 20°C. What is the entropy generation for this process?
The waste heat from this engine is rejected to a nearby lake at 60°F at a rate of 800 Btu/min. Determine the power output of the engine. (23 hp). Determine the temperature of the source. (1156
Calculate thermistor temperature sensitivity for a thermistor at 100oC. Thermistor Resistance at 100oC is 100 ohms. Take Beta = 4120 k @ 100oC.
The exit temperature of hot air is 20°C. (Assuming constant specific heats.) What is the exit temperature of the cold water?
Heat transfer coefficient between gas and each wire is 200 w/m2-k. Estimate the conduction error in the measurement of gas temperature. The wire is 5 cm long and 1.5 mm in diameter.
Determine the surface temperature of the top of the puck after an 83 MPH (37 m/s) slapshot from center ice by Paval Datsyuk. The ice temperature is -4°C.
Compare air and helium as cooling media for electronic devices. Both fluids must exit through an area of 0.025 m^2. The exit temp is limited to 60 c the inlet temp can be as low as 10 c and as high
If the volume of the air in the tank is 2 cubic meters, find the increase in entropy of the air during the process. Assume that the specific heat of the air is constant.
Determine the amount of heat transferred (kJ) during the process. Treat the Hydrogen as an ideal gas and use constant specific heats at the average temperature.
The air is then reheated until a final state of 80 oF and 40% relative humidity is reached. Determine: The mass flow rate of the condensate leaving the unit.
The coefficient of performance of the air-conditioning unit is 2.92. Determine: the input power to the vapor-compression refrigeration system per unit mass of dry air.
Combustion products (2% water vapor and 98% dry air by mass) flow in a chimney at 34oC and 1 atm. Determine: a. The dew point temperature b. The humidity ratio c. The relative humidity.
Determine the relative humidity and the humidity ratio of the air. Determine the mixture volume (ft3) containing 1 lbm of dry air.
A stirring rod transfers energy by work until the pressure is 2 bar. The air behaves as an ideal gas. Determine the work, in kJ, and the amount of entropy produced, in kJ/K. Comment.
For each process of a closed system, show the initial and final states on a properly-labeled T-s diagram, evaluate the change in entropy, and apply the entropy balance and energy balances.
Is it economical to increase the carburizing temperature to 1000C? Justify your answer. The activation energy for difussion of C in Fe is 32,900 cal/mole and R is 1.987 cal/mol.K.
Calculate the critical heat flux on a large horizontal surface for the following fluids at 1 atm: mercury, ethanol, and refrigerant R-134a. Compare these results to the critical heat flux for water
Determine: The maximum theoretical power that can be developed by the turbine, in MW, and the corresponding turbine exit temperature.
A cup of coffee (12oz) 0.0125 ft^3 that is at 140 degrees F sits on a desk. Calculate. The amount of heat transfer from the coffee, in Btu. The entropy produced during the process, But/degrees R.
Stray heat transfer and kinetic and potential energy effects are negligible. Determine (a) the isentropic turbine efficiency and (b) the rate of entropy production within the turbine, in KW/K.
Hydrogen at 25 bar, 450°C enters an adiabatic turbine and expands to 2 bar, 160°C with a mass flow rate of 0.2 kg/s. Determine the power produced and the isentropic efficiency.
Determine (a) the temperature of the refrigerant exiting the compressor, in °C (b) the power input to the compressor, kW and (c) the rate of entropy production kW/K.
Saturated liquid water is heated at constant pressure in a steady-flow device until it is a saturated vapor. Calculate the heat transfer, in kJ/kg, when the vaporization is done at a pressure of 80
It strikes the smooth ground at a distance of 20 ft away and bounces upward at 30 degrees. Determine the initial velocity, final velocity, and coefficient of restitution between the ball and the gro