A spherical shaped orange (k= 0.3W/m℃) 80mm in diameter undergoes ripening process and generates 5000W/m3 of energy. If external temperature of orange is 10℃ and it is surrounded by air having heat transfer coefficient 20W/m2-k then the maximum temperature (℃) in at the centre of orange will be
Question 2
A fluid (Prandtl number, Pr = 1) at 500 K flows over a flat plate of 1.5 m length, maintained at 300 K. The velocity of the fluid is 10 m/s. Assuming kinematic viscosity, ν = 30 × 10 − 6 m2/s, the thermal boundary layer thickness (in mm) at 0.5 m from the leading edge is __________
Question 3
Match the following:
List 1
P) Stanton number
Q) Grashof number
R) Peclet number
S) Schmidt number
List 2
1) Natural convection for ideal gas
2) Mass transfer
3) Forced convection
4) Forced convection for small Prandtl number
Question 4
The temperature distribution in a body is given by :
What is the value of , considering there is no internal heat generation inside the slab and(thermal diffusivity) remains constant through out the time
Question 5
What is the value of the view factor for two inclined flat surfaces having a common edge of equal width, and with an angle of 20 degrees?
Question 6
A counter flow heat exchanger is used to heat from 200C to 800C by using hot exhaust gas entering at 1400C and leaving at 800C. the log mean temperature difference for the heat exchanger is
Question 7
Heisler chart shows the temperature time history of a solid in a transient heat conduction as a function of:
Question 8
On increasing the heat transfer coefficient then the efficiency and the effectiveness of the fin respectively are
Question 9
A heat exchanger is used to cool down hot water for a process plant. The hot water of mass flow rate 0.035 kg/s enters at 370 ℃and leaves at 300℃while the cooling water of mass flowrate 0.027 kg/s enters at 270℃and 218℃. Take specific heat of both the fluids as 4087 J/kg℃.The fraction of heat loss through Heat exchanger is
Question 10
For the circular tube of equal length and diameter shown below, the view factor F13 is 0.17. The view factor F12 in this case will be
, considering there is no internal heat generation inside the slab and 
(thermal diffusivity) remains constant through out the time
