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NATURAL CONVECTION HEAT TRANSFER

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Natural convection heat transfer takesplace when a vertical hot plate comesin contact with a quiescent colderuid.

Fluid layer in contact with the hot platehaving lower density ows upwardand the space is lled up by theheavier colder uid coming from thebulk.

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-g

Pressure gradient in theboundary ayer !ust be

e"ua to the #ressuregradient in the "uies$entregion%

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Energy e"uation

The &rst ter! on RHS isbuoyan$y 'or$e in(o(ingdensity di)eren$e *hi$horiginates the +o*%

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THE ,O,ENTU, AN ENER./E0UATION ARE COUPLE 1/RE,OVIN. ENSIT/ AN

INTROUCIN. TE,PERATURE%

The 'un$tiona 'or! o' heattrans'er $oe2$ient his gi(en by3

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FOLLO4IN. PI-THEORE,THERE ARE 5 VARIA1LESAN 6 I,ENSIONS ARE

INVOLVE IN THEPRO1LE,%

THEREFORE 7 5-6I,ENSIONLESS .ROUPSARE POSSI1LE% THE/ ARE3

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.RASHOF NU,1ER

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ANAL/SIS OF NATURAL CONVECTION

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RA/LEI.H NU,1ER

N 8 9:6 ;a!inar+o*