課程名稱︰熱力學
課程性質︰
課程教師︰許文翰
開課系所︰工科海洋系
考試時間︰94.6.21
試題 :
1.An engine operates on the air-standard Otto cycle.The pressure and the
temperature at the begining of isentropic compression are 120kPa and 35。C
﹐respectively.The peak pressure and temperature are 4.8MPa and 2500。C.
Determine (a)the net cycle work in kJ/kg;(b)the cycle efficiency.(20％)
2.An engine operates on the air-standard diesel cycle with a compression
ratio of 18.The pressure and the temperature at the begining of compression
are 120kPa and 43。C.The maximum temperature is 1992K and the heat added is
1273kJ/kg.Determine (a)the maximum pressure;(b)the temperature at the
begining of heat addition.(20％)
3.In an air-standard Brayton cycle,the compressor inlet conditions are
100kPa and 280K.The turbine inlet conditions are 1000kPa and 1167K.The
turbine produce 11190kW.Determine (a)the air flow rate;(b)the cycle
efficiency;(c)the second-law efficiency.(20％)
4.A double-acting single-cylinder reciprocating air compressor has a piston
displacement of 0.015m^3 pre revolution,operates at 500rev/min,and has
a 4％ clearance.The air is received at 96kPa and delivered at 584 kPa.
The compression and expansion processes obey pV^1.35=C.Determine (a)
the power required;(b)the volumetric efficiency;(c)the heat transfer
during compression if T1=289K.(20％)
5.Three kilograms of air are heated from 300K to 800K while the pressure
changes from 100kPa to 500kPa.Determine the change in entropy.(20％)
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.112.244.123