Mechanical Engineering Answers

1. Analyze the structure of some problem for the company/project by Interpretive Structural Modeling (ISM).

A Carnot engine operates between two temperature reservoirs maintained at 493.15K and 298.15K, respectively. If the desired output of the engine is 20.00 kW, find the heat transfer to the low temperature reservoir.

A thin rim is made by joining two halves with rivets as shown in figure 3.8. Determine the required diameter of the twelve rivets if the rim must rotate at 600 r/min and the allowable shear stress in the rivets is 63 MPa. Ignore the effect of the cover plates. The density of the material used 7800 kg/m3 

In a slider crank mechanism, the length of the crank and connecting rod are 100 mm 

and 400 mm respectively. The crank rotates uniformly at 600 r.p.m. clockwise. When the crank 

has turned through 45° from the inner dead centre, find, by analytical method : 1. Velocity and 

acceleration of the slider, 2. Angular velocity and angular acceleration of the connecting rod. 

Check your result by Klein’s construction. 

[Ans. 5.2 m/s; 279 m/s2; 11 rad/s; 698 rad/s2]

The dimensions of various links in a mechanism, as shown in Fig. 6.34, are as 

follows : A B = 25 mm ; BC = 175 mm ; CD = 60 mm ; AD = 150 mm ; BE = EC ; and EF = FG 

= 100 mm. The crank A B rotates at 200 r.p.m. When the angle BAD is 135°, determine by 

instantaneous centre method : 1. Velocity of G, 2. Angular velocity of EF, and 3. Velocity of 

sliding of EF in the swivel block S. [Ans. 120 mm/s ; 6.5 rad/s ; 400 mm/s]

Investigate and explain the procedure by which mechanical engineers or motor mechanics fasten engine bolts using a ratchet.

the capacity of a refrigeration is 200tr when working between -6°C and 25°C also find the power requirement to drive the unit

A balloon in its flat and collapsed state is filled with helium gas at constant pressure 101 kPa slowly. If it attains a sphere of radius 0.8 m during the reversible process, estimate the work done by helium.

A certain mass of air is initially at 267°C and 7 bar occupies 0.21 m3. The air is expanded at. constant pressure such that volume becomes three times the initial volume. A polytropic process with n =1.3 is then carried out, followed by an isothermal process which completes the cycle. Considering all the processes reversible, find : (i) The heat rejected and received during each process. (ii) Net work done during the cycle. iii) Sketch the cycle on p-V and T-s diagram.

 A compound thin cylinder has a common diameter of 100 mm and the inner cylinder has a thickness of 2,5 mm. The radial pressure between the two cylinders is 200 kPa and the difference between the two common diameters before shrinkage was 4,305 x 10-3 mm. Determine (a) the thickness of the outer cylinder; and (b) the resultant hoop stresses in both cylinders if the compound cylinder is subjected to an internal pressure of I80 kPa (E = 200 GPa).