QUESTION 2 Note: Work accurately to two decimal places. Use a point (.) as your decimal place holder. A horizontal single cylinder engine has a cylinder diameter of 75 mm, a radius of crankshaft 70 mm and a connecting rod length of 393 mm. The mass of the piston is 7 kg and that of the connecting rod is 7 kg. The centre of mass of the connecting rod is 199 mm from the big end bearing centre and has a radius of gyration k = 254 mm through the centre of gravity of the connecting rod. The effect of the connecting rod mass may be allowed for by apportioning it between the two ends. When the crank is 54° from the top dead centre position on the compression stroke (piston moving towards (TDC) the gas pressure is 849 kPa. The crankshaft rotates at a rotational speed of 924 rpm. 2.1 Calculate the reciprocating mass (R) of the system [answer in kg]. 2.2 Calculate the kinetic energy of rotation of the connecting rod (E), through its centre of gravity [answer in Joule]. 2.3 Calculate the velocity of the piston (vp) [answer in m/s] 2.4 Calculate the acceleration of the piston (fp) [answer in m/s2] 2.5 Calculate the transition angle (θT) for the configuration [answer in degrees]. 2.6 Calculate the force on top (Ft) of the piston due to the gas pressure [answer in N] 2.7 Calculate the resultant net force (Fnet) on the piston [answer in N] 2.8 Calculate the force in the connecting rod (Q) [answer in N] 2.9 Calculate the torque (T) on the crankshaft [answer in Nm]
QUESTION 2
Note: Work accurately to two decimal places. Use a point (.) as your decimal place holder.
A horizontal single cylinder engine has a cylinder diameter of 75 mm, a radius of crankshaft 70 mm and a connecting rod length of 393 mm. The mass of the piston is 7 kg and that of the connecting rod is 7 kg. The centre of mass of the connecting rod is 199 mm from the big end bearing centre and has a radius of gyration k = 254 mm through the centre of gravity of the connecting rod. The effect of the connecting rod mass may be allowed for by apportioning it between the two ends. When the crank is 54° from the top dead centre position on the compression stroke (piston moving towards (TDC) the gas pressure is 849 kPa. The crankshaft rotates at a rotational speed of 924 rpm.
2.1 Calculate the reciprocating mass (R) of the system [answer in kg].
2.2 Calculate the kinetic energy of rotation of the connecting rod (E), through its centre of gravity [answer in Joule].
2.3 Calculate the velocity of the piston (vp) [answer in m/s]
2.4 Calculate the acceleration of the piston (fp) [answer in m/s2]
2.5 Calculate the transition angle (θT) for the configuration [answer in degrees].
2.6 Calculate the force on top (Ft) of the piston due to the gas pressure [answer in N]
2.7 Calculate the resultant net force (Fnet) on the piston [answer in N]
2.8 Calculate the force in the connecting rod (Q) [answer in N]
2.9 Calculate the torque (T) on the crankshaft [answer in Nm]
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