Nusselt number Definition and 13 Threads

So firstly, I don't understand if the mass flow rate is for steam or for water. If it is for water, I know I can find the heat transfer rate using equation:Q=mcdeltaT. But then I don't know how to find h (the average heat transfer coefficient) because I don't know the surface area (As). I can...

Hi there, Hopefully this is a very easy question and you all can just confirm this for me. When calculating heat transfer into a fluid from a heated tube, is it correct to say that the heat transfer coefficient is *not* dependent on the tube diameter? So, if we solve for T_{out}, we get...

The Nusselt number represents the ratio of heat transfer by convection relative to conduction. At the onset of convection does this correspond to a Nusselt number of 1?

Anyone knows if i can calculated Nusselt number for a developing turbulent flow in the entrance region for a duct/ tube?

I am looking for a Nusselt number correlation that will work for a shell & tube heat exchanger in the Re < 3000 region, i.e. extremely laminar flow (for a lab experiment). I've been searching for a while now, but can only find empirical correlations for Re > 3000, and was thus hoping that...

I am trying to find an expression for the average Nusselt number corresponding to heat transfer from an isothermal disk. Given: ShD≡hm(r)D/DAB=Sho[1 + a (r/ro)n] (1) Sho=hm(r=0)D/DAB=0.814ReD1/2Sc0.36 (2) Relevant equations: Average nusselt number is defined as Nuav=havD/k where k...

The Nusselt number for an entire flat plate in the turbulent region has two different equations: One for Turbulent and one for Combined Laminar and Turbulent. How do I know when to use one or the other?

So, in Nu=\frac{hD}{k} h is the heat transfer coefficient, and D is the diameter of the pipe in which heat transfer takes place... ..but what are the dimensions of k in terms of mass (M), length (L), time (T) and temperature (\theta)? So far, I've worked out that the units for h...

Homework Statement A common dimensionless group used in heat transfer calculations is defined as: Nu=\frac{hD}{k} where h is the heat transfer coefficient, and D is the diameter of the pipe in which heat transfer takes place. Please determine the dimensions of the quantity k in...

Hi everybody I built a cavity model in Ansys in order to modelling natural convection heat transfer inside a heat exchanger. But I do not know how to export Nusselt number over time. I need to see how it varies while time passing. Please help me. I know that from Reports part of software I can...

Homework Statement See the picture for the homework problem: http://i41.tinypic.com/2drk2x.png Homework Equations I'm having trouble converting between the first equation and the second one. I understand that Nu_x=h_x*x/k Re = rho*v*x/visc Pr = c_p*visc/k But how the heck do I...

Hi i need to calculate nusselt number for stimulation of air flow in a pipe with 5mm diameter and the pressure is 5atm. it should be in the form: Nu = N1 + N2 Re^N3*Pr^N4 and i want to calculate N1,N2,N3,N4. but i don't know how? can anyone Help?

Hello I need to calculate the Nusselt number for liquid sodium in a pipeline. Length of the pipeline is 3 meter. Diameter of the pipeline is 0.3 meter. Heat flux through outer surface of the pipeline is equal zero. Temperature on the right side and left side of the pipeline is 573 K and 773 K...