Heat Transfer - Engineering

Q1:

The heat flux in the nucleate boiling regimes is proportional to (where, ΔT = excess temperature)

A ΔT)2

B (ΔT)4

C (ΔT)3

D (ΔT)

ANS:C - (ΔT)3

In the nucleate boiling regime, the heat flux (q) is often described by the following correlation: q∝(ΔT)n Where ΔT is the excess temperature, and n is an exponent that depends on the specific conditions. Typically, experimental data and theoretical analysis suggest that for nucleate boiling, the heat flux is approximately proportional to 3/2(ΔT)3/2 or (Δ)2(ΔT)2. However, there is no universal consensus on the exact power exponent. Given the options provided, the most common approximation for the heat flux in nucleate boiling is proportional to 2(ΔT)2. Therefore, the correct answer is: (ΔT)2