Critical value of the _____________ number governs the transition from laminar to turbulent flow in free convection heat transfer?

Related Mcqs:

For a laminar flow of fluid in a circular tube, ‘h1’ is the convective heat transfer co-efficient at velocity ‘V1’. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is________________?

A. 1.26 h1 B. 0.794 h1 C. 0.574 h1 D. 1.741 h1...

Tube expansion allowances exist in _____________ heat exchanger?

A. Multipass fixed tube sheet B. U-tube C. Single pass fixed tube sheet D. None of these...

A _____________ evaporator employs an annular downtake?

A. Basket type B. Horizontal C. Long tube vertical D. None of these...

For hot feed, forward feeding as compared to backward feeding results in ______________ economy?

A. Increased B. Decreased C. No effect on D. None of these...

The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of ‘a’ in SI system will be________________?

A. W/m.k B. W/m C. W/m.k2 D. None, ‘a’ is just a number...