MECH 3800
Assignment # 4
Due: October 7th, 2011, 4:30
1. An ideal gas refrigeration system with two stages of compression with intercooling is shown
in the following figure. It operates with air entering the first compressor at 90 kPa and -18C.
Each compr
MECH 3800
Tutorial # 10
November 25th, 2011
1. Air at 1 MPa, 600C enters a converging nozzle with a velocity of 150 m/s.
Determine the mass flow rate through the nozzle for a throat area of 50 cm2 when the
back pressure is 0.7 MPa and 0.4 MPa. Determine a
MECH 3800
Tutorial # 9
November 11th, 2011
1. Acetylene (C2H2) gas at 25C is burned with 140% theoretical air which enters the
burner at 25C, 100 kPa and 80% relative humidity. The combustion products form a
mixture of CO2, H20, N2, O2 and NO in chemical
MECH 3800
Tutorial # 8
November 4th, 2011
1. (Midterm 2001) Consider the following gas turbine plant for combined power and
steam production. Liquid octane (C8H18) is injected into the combustion chamber of a
gas turbine engine at 298 K at a rate of 1 kg/
MECH 3800
Tutorial # 7
October 28th, 2011
1. H2 enters a combustion chamber with a mass flow rate of 2 kg/h and burns with air
entering at 30C, 1 atm with a volumetric flow rate of 120 m3/hr. Determine the
percent theoretical air used. Write the balanced
MECH 3800
Tutorial # 6
October 21st, 2011
1. (MIDTERM 2003) An A/C unit at steady-state takes in moist air at 35C, 75%
relative humidity, and 95 kPa. The moist air first passes over a cooling coil in the
dehumidifier section and some water vapor is conden
MECH 3800
Tutorial # 5
October 7th, 2011
1. Natural gas at 23C, 1 bar enters a furnace with the following molar analysis: 40% propane
(C3H8), 40% ethane (C2H6), 20% methane (CH4). Determine
a)
b)
c)
the analysis in terms of mass fraction
the partial press
MECH 3800
Tutorial # 4
September 30th, 2011
1. Consider a two-stage cascade refrigeration system with R-134a operating between 0.1
MPa and 1.2 MPa. Heat rejection from the lower cycle to the upper cycle takes place
in an adiabatic counter flow heat exchan
MECH 3800
Tutorial # 2
September 16th, 2011
1. A tank having a volume of 0.85 m3 initially contains water as a two-phase liquidvapor mixture at 260C and a quality of 0.7. The tank is now heated. In order to keep
the pressure constant, saturated vapor at 2
MECH 3800
Tutorial # 3
September 23rd, 2011
1. Refrigerant 134a is the working fluid in an ideal vapor compression refrigeration
cycle. The refrigerant leaves the evaporator at -20C and the condenser pressure is
0.9 MPa. The mass flow rate of the refriger
MECH 3800
Tutorial # 1
September 9th, 2011
1. A mass of 15 kg of air at 300 kPa in a piston cylinder device is heated from 25C to
77C by passing a current through a resistance heater inside the cylinder. During this
process a heat loss of 60 kJ occurs. De
MECH 3800
Practice Problems
1. In a test of a gas-turbine combustor, saturated liquid methane at 115 K is burned with
excess air to hold the adiabatic flame temperature to 1600 K. It is assumed that the
products consist of a mixture of CO2, H2O, N2, O2 an
MECH 3800
Assignment # 10
Due: December 2nd, 2011, 16:30
1. A given convergent nozzle operates so it is choked with stagnation inlet flow
properties of 400 kPa, 400 K. To increase the flow, a reversible adiabatic compressor
is added before the nozzle to i
MECH 3800
Assignment # 9
Due: November 25th, 2011, 16:30
1. Calculate the equilibrium constant for the reaction 2CO2 2CO + O2 at 3000 K.
Compare the result with table A.11.
2. A gaseous mixture with a molar analysis of 20% CO2, 40% CO, and 40% O2 enters a