How do you find the heat transfer coefficient of a Nusselt number?

Formula

1. Nusselt Number : Nu = hL/k.
2. Convection Heat Transfer Coefficient : k = Nuk/L.
3. Characteristic Length : L = Nuk/h.
4. Thermal Conductivity of the Fluid : k = hL/Nu.
5. Where, Nu = Nusselt Number, h = Convection Heat Transfer Coefficient, L = Characteristic Length, k = Thermal Conductivity of the Fluid.

How do you find the heat transfer coefficient using Reynolds number?

Reynolds number: Re = ρUL/μ ≡ UL/ν (forced convection). A measure of the balance between the inertial forces and the viscous forces. Nusselt number: Nu = hL/kf This can be considered as the dimensionless heat transfer coefficient.

Is Nusselt number a fluid property?

In fluid dynamics, the Nusselt number (Nu) is the ratio of convective to conductive heat transfer at a boundary in a fluid. Convection includes both advection (fluid motion) and diffusion (conduction).

How do you calculate the heat transfer coefficient of a liquid?

As the mass flow may be calculated with dm = dv x ρ (volume flow times density) we will get the “qualitative” Heat transfer coefficient αm . Using: T2, T1 the inlet and outlet temperature of the fluids and the volume flow. The heat loss is also taken as constant.

What is the formula of Nusselt number?

Nusselt number basically calculated by using the formula (Nu=((hLc)/k), Where h- convective heat transfer coefficient, Lc is characteristic length. In your case, the distance between parallel plates is Lc. and Finally k is thermal conductivity of the material. If the flow is laminar, conductive heat transfer dominates.

How do you find the Nusselt number of a laminar flow?

The Nusselt number is defined as the ratio of convection heat transfer to fluid conduction heat transfer under the same conditions….19.6 Heat Transfer Correlations.

What is Nusselt number formula?

How do you calculate transfer coefficient?

The most common way of doing this is by dividing the thermal conductivity of the convection fluid by a length scale. It is also common to calculate the coefficient with the Nusselt number (one of a number of dimensionless groups used in fluid dynamics).

What does Nusselt number depend on?

The Nusselt number in the fully developed laminar flow is constant and depends on the channel geometry and the wall heat transfer boundary condition.

How do you calculate overall heat transfer coefficient in heat exchanger?

The overall heat transfer coefficient R = Resistance(s) to heat flow in pipe wall (K/W) Other parameters are as above. The heat transfer coefficient is the heat transferred per unit area per kelvin. Thus area is included in the equation as it represents the area over which the transfer of heat takes place.

What is the Nusselt number of a fluid layer?

A Nusselt number of Nu=1 for a fluid layer represents heat transfer across the layer by pure conduction. The larger the Nusselt number, the more effective the convection. A larger Nusselt number corresponds to more effective convection, with turbulent flow typically in the 100–1000 range.

What is the Nusselt number of conductive component?

The conductive component is measured under the same conditions as the heat convection but with a stagnant fluid. The Nusselt number is to the thermal boundary layer what the friction coefficient is to the velocity boundary layer. Thus, the Nusselt number is defined as:

Why is the Nusselt number constant for laminar flow?

Therefore, for fully developed laminar flow in a circular tube subjected to constant surface heat flux, the Nusselt number is a constant. There is no dependence on the Reynolds or the Prandtl numbers.

What is the relation between Nusselt number and Reynolds number?

For turbulent flow, the Nusselt number is usually a function of the Reynolds number and the Prandtl number. This relation gives the average heat transfer coefficient for the entire plate when the flow is laminar over the entire plate.