A four-cylinder four-stroke engine is operating at a bmep of 2 bar. The pressure at inlet...

A four-cylinder four-stroke engine is operating at a bmep of 2 bar. The pressure at inlet valve closure is 0.37 bar, and the fmep is 0.8 bar. Assuming that the engine gross indicated efficiency is unchanged, verify that disablement of the valves on two cylinders would reduce the fuel consumption by about 13 per cent compared with about an 8 per cent fuel saving if the fuel was not supplied to two cylinders. Assume that the gross imep is proportional to the pressure at inlet valve closure, and that the gross indicated efficiency is constant. State any additional assumptions that you make. By means of p–V diagram sketches, explain why disabling only the inlet or exhaust valves would have a fuel economy benefit comparable to fuel disablement to two cylinders.

Expert Solution

samet mamat answered 2 years ago

The 12 cylinder 2 stroke cycle compression ignition engine of an oil tanker is operating at...

The 12 cylinder 2 stroke cycle compression ignition engine of an oil tanker is operating at 150 rpm The brake mean effective pressure of the engine is 400 kPa and the excess air coefficient is 2. The crankshaft of the engine is directly coupled to a propeller and a torque of 1500 kN-m is applied. The engine operates on light fuel oil which can be approximated as C12H26. If the brake specific fuel consumption is 200 g/hp-h what is the...

1. An aluminum air-cooled engine cylinder head for a single cylinder, 2-stroke engine is to be...

1. An aluminum air-cooled engine cylinder head for a single cylinder, 2-stroke engine is to be die-cast. The overall diameter of the cylinder head is 101.6 mm. If the projected plan area of the runners and gating system is 100 mm2 and the casting pressure is 10 MPa (1500 psi), what minimum locking force is required for the die-casting machine in kN.

A single-cylinder, four stroke research engine operates on Otto cycle. The specification of the engine is...

A single-cylinder, four stroke research engine operates on Otto cycle. The specification of the engine is shown as below:- Displacement volume of the cylinder = 540 cm3 Clearance volume of the cylinder = 60 cm3 Minimum temperature = 200°C Minimum pressure = 200 kPa Net work output = 1000 kJ/kg Sketch the process on a P-V diagram and by using constant specific heat at room temperature, determine: i) the temperature and pressure at each process, ii) the thermal efficiency of...

A two-cylinder, four-stroke gas engine has a bore of 380 mm and a stroke of 585...

A two-cylinder, four-stroke gas engine has a bore of 380 mm and a stroke of 585 mm. At 240 rev/min the torque developed is 11.86 kNm. If the engine is supplied with a mixture of gas and air in the proportion of 1 to 7 by volume. The estimated volumetric efficiency is 85% and the Qnet,p of the gas is 38.6 MJ/m3. Calculate the brake thermal efficiency of the engine.

A 5-cylinder square engine with a total stroke volume of 3.5 liters, operating according to a...

A 5-cylinder square engine with a total stroke volume of 3.5 liters, operating according to a 4-stroke cycle, operates at 2500 rpm. Since the mechanical efficiency of the engine is 62% and the Indicative work produced for each cylinder is 1 kJ, find the specific power of the engine in kW / cm2.

A test was conducted on a 4-stroke four cylinder engine having 6.9 cm diameter and 8.9...

A test was conducted on a 4-stroke four cylinder engine having 6.9 cm diameter and 8.9 cm stroke. The fuel supply to the engine is 0.065 kg/min. The B.P measurements are given below with constant engine speed of 300 rpm: With all cylinder firing = 16.9 kW Cut off at 1st cylinder = 8.46 kW Cut off at 2nd cylinder = 8.56 kW Cut off at 3rd cylinder = 8.6 kW Cut off at 1st cylinder = 8.46 kW If...

A 4 cylinder 4 stroke 2.3 L diesel engine with bore = 12.4 cm and stroke...

A 4 cylinder 4 stroke 2.3 L diesel engine with bore = 12.4 cm and stroke =11 cm. the crank radius is 6.2 cm and with a connecting rod length 15 cm. the compression ratio of the engine is 20 and the combustion efficiency is 97.3 %. If the average speed of the car over the running life of the engine is 56 km/h and the total traveled distance of the engine is 250000 km. note: use the engine speed...

A 2-stroke motor cycle petrol engine cylinder consists of 15 fins. If the outside and inside...

A 2-stroke motor cycle petrol engine cylinder consists of 15 fins. If the outside and inside diameter of each fin are 200 mm and 100 mm respectively, the average fin surface temperature is 475 c and atmospheric air temperature is 25 c calculate the heat transfer rate from the fins when the motor cycle is stationary.Assume all the fins in a horizontal position.

1) A four-stroke diesel engine has a piston diameter of 16.5 cm and a stroke of...

1) A four-stroke diesel engine has a piston diameter of 16.5 cm and a stroke of 27 cm. The compression ratio is 14.3, the cut-off 4.23% of the stroke and the mean effective pressure 4.12 bar. The engine speed is 264 rev/min and the fuel consumption is 1.076 kg of oil per hour, having a calorific value of 39150 kJ/kg. Calculate the relative efficiency of the engine 2). A diesel engine has a brake thermal efficiency of 30%. If the...

During the power stroke in a four-stroke automobile engine, the pis-ton is forced down as the...

During the power stroke in a four-stroke automobile engine, the pis-ton is forced down as the mixture of combustion products and air undergoes an adiabatic expansion. Assume (1) the engine is running at 2500 cycles/min; (2) the pressure immediately before the expansion is 20.0 atm; (3) the volumes of the mixture immediately before and after the expansion are 50.0 cm3and 400 cm3, respectively ; (4) the time interval for expansion is one-fourth that of the total cycle; and (5) the...

Question