Diesel fuel (c12h26) at 25°c is burned in a steady flow combustion chamber. the air also enters the combustion chamber at 25°c. the products leave the combustion chamber at 500 k. compare between the required mass flow rate for 20 percent excess air and 140 percent stoichiometric air of the complete combustion of diesel fuel to supply heat at a rate of 2000 kw. [15 marks] take the molar mass of c12h26 as 170.3348 g/mol. (b) a 3.2-liter si engine is to be designed with bowl-in-piston combustion chambers. with a central spark plug and combustion at tdc, this gives a flame travel distance of b/4. the engine is to operate with an average piston speed of 8 m/sec and a burn angle of 25° of engine crank rotation. stroke and bore will be related by s-0.95 b. mathematically evaluate the average flame speed for both v4 and v8 engines.