Q78 A four cylinder, four-stroke Petrol engine has a compression ratio of 6 to 1. A test on this engine gave the following results; Net brake load = 20 kg, effective brake arm = 0.5 m, indicated mep=6*105 N/m², engine speed 2400 rpm, fuel consumption = 10 kg/h, Calorific value of the fuel = 44000kj/kg, Cylinder bore 86 mm, engine stroke-100mm. ข่าวล Calculate: the mechanical efficiency, ⑥the brake thermal efficiency the relative efficiency assuming the engine works on the Constant volume cycle and that 8-1.4 forair ⑧The brake mean effective pressure. Answers 1 88.4%, 48/5-35 × 105 N/m² 1 و و

1 A six-cylinder, gasoline engine operates on the four-stroke cycle. The bore of each cylinder is 80 mm and the stroke 100 mm. The clearance volume per cylinder is 70 cc. At a speed of 4000 rpm the fuel consump- tion is 20 kg/h and the torque developed is 150 Nm. Calculate (i) the brake power (ii) the brake mean effective pressure (iii) brake thermal efficiency if the calorific value of the fuel is 43000 kJ/kg and (iv) the relative efficiency on a brake power basis assuming the engine works on the constant volume cycle. y = 1.4 for air.

A four-cylinder, four-stroke diesel engine has a bore of 212 mm and a stroke of 292 mm. At full load at 720 rev/min the bmep is 5.93 bar and the specific fuel consumption is 0.226 kg/kW h. The air-fuel ratio as determined by exhaust gas analysis is 25/1.Calculate the brake thermal efficiency and the volumetric efficiency of the engine. Atmosphenc conditions are 1.01 bar and 15°C, and Qnet.p, for the fuel may be taken as 44 200 kJ/kg (36%: 76.1%) 13.6

Q1. During a test on a two stroke diesel engine on full load the following observations were recorded: Speed= 350 rpm Net brake load= 590 N Mean effective pressure= 2.8 bar Fuel consumption=4.3 kg/h Jacket cooling water= 500 kg/h Temperature of jacket water at inlet and outlet= 25°C and 509C respectively Air used per kg of fuel= 33kg Temperature of air in test room= 25°C Temperature of exhaust gases= 400°C Cylinder diameter= 220 mm Stroke length= 280 mm Effective brake diameter= 1 m Calorific value= 43900 KI/kg Proportion of hydrogen in fuel= 15% Mean specific heat of dry exhaust gases= 1.0 KI/kg K Specific heat of steam= 2.09 KJ/kg K Calculate: (1) indicated power (2) brake power (3) draw up heat balance sheet on minute basis.

Engine Type Four cylinder Four stroke Diesel engine, Bore: 0.073m, Stroke: 0.0889m Capacity : 1489cc, Power 36 H.P. at 4000 rpm, Torque: 8.5 kg.m at 2250 rpm and Compression Ratio :17.3:1 Explain how to measure the :- (i) Fuel consumption. Manometer readings for air flow. (iii) RPM, power output etc. (iv) Study of various components of diesel engine.

Q2/ A six-cylinder, gasoline engine operates on the four-stroke cycle. The bore of each cylinder is 80 mm and the stroke is 100 mm. The clearance volume per cylinder is 70 cc. At the speed of 4100 rpm, the fuel consumption is 5.5 gm/sec (or 19.8 kg/hr.) and the torque developed is 160 Nm. Calculate: (1) Brake power, (ii) The brake mean effective pressure, (iii) Brake thermal efficiency if the calorific value of the fuel is 44000 kJ/kg and (iv) The relative efficiency on a brake power basis assuming the engine works on the constant volume cycle = 1.4 for air. thon tected the following observations available :

1. An 11.1 liter, 6 cylinder, 4 stroke engine has a 120 mm bore and 125 mm stroke. If its compressions ratio is 16, what is the clearance volume? What is the engine displacement per minute if it runs at 2,000 rpm? If biogas, with an energy content of 4,500 Kcal/m3 will be fueled into the engine, what would be its power output (in KW) considering a 10% brake thermal efficiency?

The following data were obtained during a test of six cylinder otto cycle engine. Speed 2000 rpm, bore 3.5 in stroke 3.75 in, specific fuel consumption base on brake hp.66 lbs. / bhp-hr, brake arm 1.05 ft. HHV of fuel 20000 Btu/lb, Brake Torque 133 ft-lb, friction torque 40 ft-lb room temperature 90 F. barometric pressure 14.7 psia Find:a.) BHP=b.) BMEP=c.) IMEP=d.) IHP=e.) BRAKE THERMAL EFFICIENCY=f.) INDICATED THERMAL EFFICIENCY=

Calculate the amount of fuel required per cylinder per stroke for a 1500 cc SI engine running at 4000 rpm and stoichiometric air fuel ratios. Assume pumping losses to be 24%

Seatwork No. 1 An SI I-2 square engine operates on a 2-stroke cycle at 2400 rpm. The average piston speed is 15 m/se and the no. of piston action is 2. When the piston is at its maximum position the remainder volume is 0.005 Liters. Determine: a. Volumetric displacement per unit time for all cylinders (m³/sec) b. Compression ratio c. Volume at Bottom Dead Center (m³)