Question

In: Mechanical Engineering

Two long concentrie cylinders have diameters of 5 and 10 cm, respectively. The inside cylinder is...

Two long concentrie cylinders have diameters of 5 and 10

cm, respectively. The inside cylinder is at 900 C and the outer

cylinder is at 100-C. The inside and outside emisivities are 0.8

and 0.4, respectively. Calculate:

a) the percent reduction in heat transfer if a cylindrical radiation

shield having a diameter of 6 cm and emisivity af 0.3 is placed

between the two cylinders.

b)discuss the effect of decreasing the shield diameter on the

percent reduction in heat transfer

c)draw the network circuit

cxraw the network circuit

Solutions

Expert Solution

percent reduction of heat transfer by radiation shield is 100-29.75 = 70.25%

B) if we decrease the shield diameter, resistance R3, R4 and R5 will increase, this wil increase the overall resistance and which decreases the heat transfer with radiation shield, which decreases the percentage in reduction wil increase

samet mamat answered 2 hours ago
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