Q. The rate of heat transfer through a pipe wall is given by following equation. For cylinder of very thin wall, q can be approximated by

View solution

Q. Graetz number is given by

View solution

Q. Harmonic mean temperature difference is given by

View solution

Q. Thermal diffusivity is given by

View solution

Q. At steady state the temperature variation in a plane wall, made of two different solids I & II is shown below. The thermal conductivity of material I

View solution

Q. In case of surface condensers, a straight line is obtained on plotting 1/U vs __________ on an ordinary graph paper.

View solution

Q. Fouling factor for a heat exchanger is given by (where, U₁ = heat transfer co-efficient of dirty surface U₂ = heat transfer co-efficient of clean surface)

View solution

Q. For a counter current heat exchanger with Tih = 80°C, T°c = 60°C, T°h = 50°C and Tic = 30°C, and the temperature difference between the two streams being the same everywhere along Z, the direction of flow of hot fluid. The temperature profile should satisfy

View solution

Q. Following number is called the __________ number.

View solution

Q. What is the logarithmic mean of r1 and r2 ?

View solution

Q. The following equation is the __________ analogy.

View solution

Q. The number given below is termed as the __________ number.

View solution

Q. Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by following equation. This is valid for the value of NRe equal to

View solution

Q. Prandtl number is given by

View solution

Q. For a liquid in laminar flow through a very long tube, when the exit fluid temperature approaches the wall temperature, the equation to be used is

View solution

Q. A graph between __________ is called Wilson plot.

View solution

Q. What is the geometric mean of two heat transfer areas A1 and A2 ?

View solution

Q. Hot water (0.01 m³ /min) enters the tube side of a counter current shell and tube heat exchanger at 80°C and leaves at 50°C. Cold oil (0.05 m³/min) of density 800 kg/m³ and specific heat of 2 kJ/kg.K enters at 20°C. The log mean temperature difference in °C is approximately

View solution

Q. In a heat exchanger, floating head is provided to

View solution

Q. Leidenfrost point is a term concerned with the

View solution