Suppose that a new gasoline engine has been invented which can operate at the maximum thermodynamic efficiency (rather than the 25% or so which characterize most realistic engines). The burned fuel reaches about 2100 degrees C inside the engine and a 50 L gas tank has about 2 GJ of fuel energy. If the engine must supply 30 hp to keep the car at a steady speed on the highway, how long will a tank of gas last?

Question 1. A Carnot engine receives 300 kJ /s heat from a heat reservoir at 500 °C and rejects heat to a sink reservoir at 30 °C. a) Make a sketch and calculate the efficiency of the engine. b) Calculate the power the engine generates. c) Calculate the rate of heat being rejected at the cold reservoir. d) Calculate the entropy change of the universe.

Q1/ Answer the following questions: 1. We can classify I.C. engines to give a clear description for any engine? Give your opinion about that. 2. Side thrust force may give an indication about the engine performance. Discuss that. 3. It is possible to increase the mechanical efficiency of the turbocharger. Do you agree? Why? 4. How is the friction force reduced? 5. If the engine designers reduce the piston skirt length as much as possible, is this considered as an advantage for the I.C. engine?

A gasoline engine uses 0.01 kg/s of fuel while delivering 55 kW of power. The heating value of the fuel is 35,000 kJ/kg and the fuel density is 900 kg/m^3. In the question that follows, select the answer that is closest to the true value. What is the thermal efficiency of the engine?