Lecture 18 External Flow

Lecture 18 External Flow - 1 MECE 4364 Heat Transfer Prof....

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
MECE 4364 Heat Transfer Prof. Dong Liu Department of Mechanical Engineering University of Houston 1 Lecture 18 Oct 19, 2010 Lecture 18 Quiz 3 1. What is the physical interpretation of the Biot number? 2. What is the physical interpretation of the Fourier number? 3. Is the lumped capacitance method likely to be more applicable for cooling a hot solid made of copper or aluminum? 4. What is the unit of convection heat transfer coefficient? 5. How does the velocity boundary layer thickness vary with distance from the leading edge for laminar flow over a flat plate? 2
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Lecture 18 External Flow 3 Lecture 18 Flow and Thermal Considerations ± When a moving fluid comes into contact with a surface at some temperature difference ( e.g. heated surface, cold fluid) the fluid will ± transfer heat to/from the surface in a process analogous to conduction (random motion of the fluid) ± advect heat away from the point of contact by its motion (bulk motion of the fluid) ± The combined effect of these two phenomena is called convection ± Convection is governed by Newton’s Law of Cooling ± Implications: ± the “direction” of heat flux can be considered normal to the surface ± the heat transfer coefficient is related of the nature of the flow ± in order to study convection heat transfer, we must also study fluid dynamics q " = hT s T ( ) heat flux [W/m 2 ] heat transfer coefficient [W/m 2 -K] surface temperature [K] fluid temperature [K] 4
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/27/2011 for the course MECE 4364 taught by Professor Lipinglui during the Winter '10 term at University of Houston.

Page1 / 6

Lecture 18 External Flow - 1 MECE 4364 Heat Transfer Prof....

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online