1)A closed system rejects 25kJ of energy during a process while experiencing a volume change of 0.1 meters cubed(0.15 to 0.05). Assuming a reversible,constant pressure process at 350kPa, determine the change in total internal energy.(kJ)
2)Consider 5 kg of air inittially at 101.3 kPa and 38 degrees Celsius. Heat is transferred to the air until Temperature reaches 260 degrees Celsius. Determine the change in total internal energy, change in total enthalpy, the heat transfer, and work done for: a) a constant-volume process b) a constant-pressure process
3)One surface of a 12-cm-thick slab (thermal conductivity, k=2.5 W/m. degree C) is maintained at 100 degree C. The other surface is exposed to a fluid at 70 degree C. and the heat transfer coefficient at this surface is 150 W/meter squared. degree C. At steady state, what is the temperature of the surface exposed to the fluid? What is the heat flux through the slab.
4)A composite wall consists of a 13-mm-thick inner layer(k1=0.17 W/m.K), a 192-mm-thick insulation layer at the middle ( k2=0.035 W/m.K), and a 20-mm-thick outer layer(k3=0.17 W/m.K). The convective heat transfer coefficients in the inside and outside are 10 and 65 W/meter squared.K, respectively, and the inside and outside air temperatures are 20 degree C. and 0 degree C., respectively.
a) Determine heat flux through the wall
b)Determine all the surface and interface temperatures( T1,T2,T3,T4)
c)Plot the temperature distribution through the composite wall using the above temperature values
5) Superheated steam (8 Mpa, 900 K) enters a turbine with a flow rate of 0.16 kg/s. The exit pressure is 15 kPa. Determine the power produced by the turbine if the process inside the turbine is isentropic (s1=s2). Assume adiabatic process (no heat transfer) and neglects changes in kinetic and potential energies.