sábado, 12 de noviembre de 2011

Forced convection

Laminar and Turbulent Flow in Tubes
Flow in laminar regime
In a laminar regime (Re<2100), takes place almost exclusively by conduction (Sieder and Tate)




Flow in transition regime:
For 2100<Re<10 000, the following expression is used:




Flow in Turbulent  regime

For fully developed turbulent flow the Nusselt number (Dittus–Boelter equation)

1. For flow over a flat plate

Laminar:



Turbulent:
2. For flow over a cylinder (Churchill and Bernstein):




3. Flow over a sphere (Whitaker):