Painterman
Mechanical
- Feb 10, 2009
- 3
Hello all,
Two questions please:
1) An SI engine with an outlet pressure (ratio) of 5.8:1 and it's exhaust gas at 1176 kJ per kg of gas. In US-Customary: 5.8bars = 84psi and 1176 kJ/kg = 505BTU/lb.
Would this be sufficient to produce 10 bars (145 psi) of pressure from a turbo charger or two turbo chargers inter cooled? The initial condition for the air to be approximately 300kJ/kg at 300K, or in US: 129 BTU/lb and 540R.
2) An SI engine with a Qhigh of 2,281kJ/kg and 2,000K (in US: 981 BTU/lb and 3,600R). How much would I have to allow for in losses of the Qhigh (minus the Qlow that is) for cooling? In other words, I am trying to establish from the basic cycle how much I have to deduct from the Work or how much do I have to add to the Q to allow for the cooling losses. Is there a formula for this or a general guide/rule?
Thanks most kindly for your help/advice.
Best regards
Painterman (DFD)
Two questions please:
1) An SI engine with an outlet pressure (ratio) of 5.8:1 and it's exhaust gas at 1176 kJ per kg of gas. In US-Customary: 5.8bars = 84psi and 1176 kJ/kg = 505BTU/lb.
Would this be sufficient to produce 10 bars (145 psi) of pressure from a turbo charger or two turbo chargers inter cooled? The initial condition for the air to be approximately 300kJ/kg at 300K, or in US: 129 BTU/lb and 540R.
2) An SI engine with a Qhigh of 2,281kJ/kg and 2,000K (in US: 981 BTU/lb and 3,600R). How much would I have to allow for in losses of the Qhigh (minus the Qlow that is) for cooling? In other words, I am trying to establish from the basic cycle how much I have to deduct from the Work or how much do I have to add to the Q to allow for the cooling losses. Is there a formula for this or a general guide/rule?
Thanks most kindly for your help/advice.
Best regards
Painterman (DFD)
