Recent content by Sahil Dev

Sorry for the late reply. I was concentarting on another subject during the past fw weeks. 1) How can you say : The convection heat transfer mode is sustained both by random molecular motion and by the bulk motion of the fluid within the boundary layer. The contribution due to random...

Homework Statement Getting an expression for the convective heat tarnsfer coefficient. Homework Equations See attached images The Attempt at a Solution I have been reading about the boundary layers. Here is an extract of my notes corresponding to thermal boundary layer and consequently my...

Homework Statement Physical meaning of Prandtl number Homework Equations See attached image The Attempt at a Solution I have been reading about the boundary layer cocept whilst doing a self study on heat tarsnfer. I have come across the diemnsionless numbers: Reynolds number...

The system is the same : cylinder filled with ammonia and outside the cylinder is benzene.Considering the above system as open system. Hence, there is mass transfer which carries with it heat. In such a case, will the quantity of heat transfer vary had the system of (cylinder) been a closed...

Sir, can you please reply to the above? With respects Sahil

Thank you, again. Considering the same problem. Let us say the system is not an open system. Now, there is mass transfer - mass of benzene from the outside of the cylinder enetring the inside of the cylinder - carrying along with it heat. In such a case, will the quantity of heat that is...

You said, YES, if the system is taken as benzene inside the cylinder. But, as I said above, insider the cylinder is ammonia and outside benzene. It is a closed system. In a closed system, there is no exchange of mass (i.e. no mass can enter) but as we said there can be exchange of heat and...

Thanks, 1) when the gas does work on the sorroundings (then it expands as a result of easing up the downward force on the system), what is the form of energy involved here (it is not 'heat' energy- for sure). 2) Similarly, when piston does wowk on the gas (if the force on the piston is...

Thank you very much for the reply. My internet had a problem from the past few days and so couldn't logon. I'm sorry to ask a bit more clarification on the above. Regarding a closed system, Now, 1) Am I right to say that the above example of the gas doing the work on the piston or piston...

Please see below

Ok. Am I right, then, to say; 1) If the gas in the cylinder expands against an external force (i.e. if you ease up the downward force on the piston), then, the gas is doing the work on the piston (i.e. on its surroundings as you had quoted in the post before the above). 2) Whereas, if the...

Thank you very much for the reply. You said; I'm sorry for this but I'm from the Civil Engineering background, so just wanted to be clear on the above statement. Do you mean as in the picture below; http://www.learnthermo.com/images/ch07/Lesson-B/7B-11-piston-cylinder+P+F.pngThat is if I...

Homework Statement Understanding the first law of thermodynamics Homework Equations The Attempt at a Solution [/B] I have been doing a self-study course on heat transfer. I have been reading from the book by Incropera and all. I understand that the first law of thermodynamics forms the very...

No. I'm doing a self study course on heat transfer as I need it for a purpose/ The previous threads were on radiation and then thermal resistance. The above questions weren't there.

Hi, I shall be grateful if someone can throw light on the heat transfer processes taking place through in this very simple example. Consider the attached image (pdf). See figure (c) which I have also marked in red block. It is pot lying on a hot plate. I want to know the heat transfer...