Page 432 - Advanced thermodynamics for engineers
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422    CHAPTER 17 GAS TURBINES




                     efficiency of 0.95. Determine the specific thrust of the engine if the converging propelling
                     nozzle is choked.
                    [285.9 m/s]
             P17.12 Consider a twin-spool turbofan engine with the fan driven by the LP turbine and the
                     compressor by the HP turbine. Separate cold and hot exhaust nozzles are used. Calculate the
                     total thrust under the following conditions.



                                Overall Pressure Ratio              25.0
                                Fan pressure ratio                  1.8
                                Turbine inlet temperature           1500 K
                                Fan, compressor isentropic efficiency  0.9
                                Turbine isentropic efficiency        0.95
                                Isentropic efficiency of each nozzle  0.95
                                Mechanical efficiency of each spool  0.99
                                Combustion chamber pressure loss    1.3 bar
                                Mass flow rate of cold nozzle flow    130 kg/s
                                Mass flow rate of hot nozzle flow     32.5 kg/s




                      Assume sea level static conditions where the ambient pressure and temperature are
                    1.0 bar and 300 K, respectively.
                    [59.1 kN]
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