Problem 1 In the standard air Otto cycle, the pressure and temperature at the beginning of...

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Problem 1 In the standard air Otto cycle, the pressure and temperature at the beginning of compression are 100 kPa and 27 C. The maximum pressure and temperature in the cycle are 7000 kPa and 2300 K. Cp = 1.005 kJ/kg-K and Cv = 0.718 kJ/kg-K. a) Calculate the compression work per kilogram of gas. b) Calculate the average effective pressure of the cycle. Problem 2 The car, which has a 6-cylinder engine with a swept volume of 2000 cc, goes from Ankara to Istanbul at a speed of 150 km/h. The weight of the car with a single driver is 1200 kg and the front projection area is 3 m2. The rolling resistance coefficient of the wheels when rubbing against the ground is 0.015, and the discharge coefficient resulting from the aerodynamic shape of the car is Cd = 0.3. If the distance between Ankara and Istanbul is accepted as 450 km and the average specific fuel consumption of the engine is 250 g/HP-hour, how many liters of fuel will be required for this trip? (The density of fuel is 0.73 g/cc and the density of air is 1.2 kg/m3). Problem 3 For a standard air ideal Otto cycle, the pressure and temperature at the start of compression are 90 kPa and 300 K, respectively. At the end of heat input at constant volume, the temperature is 2300 K. The compression ratio is 9.5. (R = 0.287 kJ/kg-K and Cp = 1.005 kJ/kg-K for the entire cycle) Calculate the following; a) Work done during compression. b) Work done during expansion c) Average effective pressure Problem 4 20 mole percent ethyl alcohol (C2H5OH) and 80 mole percent gasoline (C7.76H13.1) are used as fuel in a spark-ignition engine. Extreme weather coefficient 1.2 Calculate the following; a) Actual air/fuel ratio by mass of reactants. b) Specific heat of reactants at constant volume at 300 C Problem 5 In the Otto cycle, the temperature and pressure of the reactants at the beginning of compression are 25 C and 90 kPa, respectively. At the end of compression, the temperature and pressure of the reactants are 320 C and 1500 kPa. The fuel used is gasoline (C7.76H13.1) and the excess air coefficient is 0.9. Calculate the following; a) Average molar specific heat of the reactants during compression. Cv (mixture) = 23.50 kJ / kmol-K b) During compression, the average specific heat of the reactants per kg, Cv (mixture) = 0.7688 kJ / kg-K c) Change in the internal energy of the reactants during compression. 1u2 = 227 kJ/kg d) Work done on the reactants during compression 1W2 = -248 kJ / kg e) Heat lost by the reactants during compression. 1Q2 = -21 kJ/kg Problem 6 Problem 1 In the standard air Otto cycle, the pressure and temperature at the beginning of compression are 100 kPa and 27 C. The maximum pressure and temperature in the cycle are 7000 kPa and 2300 K. Cp = 1.005 kJ/kg-K and Cv = 0.718 kJ/kg-K. a) Calculate the compression work per kilogram of gas. b) Calculate the average effective pressure of the cycle. Problem 2 The car, which has a 6-cylinder engine with a swept volume of 2000 cc, goes from Ankara to Istanbul at a speed of 150 km/h. The weight of the car with a single driver is 1200 kg and the front projection area is 3 m2. The rolling resistance coefficient of the wheels when rubbing against the ground is 0.015, and the discharge coefficient resulting from the aerodynamic shape of the car is Cd = 0.3. If the distance between Ankara and Istanbul is accepted as 450 km and the average specific fuel consumption of the engine is 250 g/HP-hour, how many liters of fuel will be required for this trip? (The density of fuel is 0.73 g/cc and the density of air is 1.2 kg/m3). Problem 3 For a standard air ideal Otto cycle, the pressure and temperature at the start of compression are 90 kPa and 300 K, respectively. At the end of heat input at constant volume, the temperature is 2300 K. The compression ratio is 9.5. (R = 0.287 kJ/kg-K and Cp = 1.005 kJ/kg-K for the entire cycle) Calculate the following; a) Work done during compression. b) Work done during expansion c) Average effective pressure Problem 4 20 mole percent ethyl alcohol (C2H5OH) and 80 mole percent gasoline (C7.76H13.1) are used as fuel in a spark-ignition engine. Extreme weather coefficient 1.2 Calculate the following; a) Actual air/fuel ratio by mass of reactants. b) Specific heat of reactants at constant volume at 300 C Problem 5 In the Otto cycle, the temperature and pressure of the reactants at the beginning of compression are 25 C and 90 kPa, respectively. At the end of compression, the temperature and pressure of the reactants are 320 C and 1500 kPa. The fuel used is gasoline (C7.76H13.1) and the excess air coefficient is 0.9. Calculate the following; a) Average molar specific heat of the reactants during compression. Cv (mixture) = 23.50 kJ / kmol-K b) During compression, the average specific heat of the reactants per kg, Cv (mixture) = 0.7688 kJ / kg-K c) Change in the internal energy of the reactants during compression. 1u2 = 227 kJ/kg d) Work done on the reactants during compression 1W2 = -248 kJ / kg e) Heat lost by the reactants during compression. 1Q2 = -21 kJ/kg Problem 6