International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 04 Issue: 07 | July -2017
p-ISSN: 2395-0072
www.irjet.net
FORCED CONVECTION HEAT TRANSFER ANALYSIS OF ZIG-ZAG CHANNEL Suneel Sharma1,Vardan Singh2 1 2
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Abstract: As things are compacting now a days so it is necessary that our heat transfer equipment’s has to reduce in size without decreasing their effectiveness.in this regard in micro channels if we implant zig zag channel for fluid flow ,it increases area of heat transfer in increasing effective length.an experiments were performed on a zigzag plate to find relation of convective heat transfer and nusselt no. Introduction: The major advantages of Zig-Zag channels includes, increased surface area for heat flow, better flow mixing at curved portion consequences in better distribution of heat, and effective cooling . In normal heat flow as in straight channel same molecule remains in contact with the surface throughout the flow causes poor heat transfer, but in wavy or zig-zag channel, due to the phenomenon known as boundary layer regeneration fluid particle from free layer gets chance to come in contact with the surface which enhances the heat transfer characteristics. But its disadvantage is that it causes pressure drop. But the value of effectiveness of channel is greater than one which shows that heat transfer enhancement is more as compared to pressure drop. In Zigzag channel as compared to straight channel the effective channel length (Le) for heat transfer increases, which allows the fluid to take more heat from the surface, which increases the fluid outlet temperature (for given temperature slope and fluid inlet temperature ) and hence increases the convective heat transfer coefficient. Physical significance of Dimensionless Numbers
For Forced convectionh=f(V,ρ,u,K,Cp,Lc)
1.
Reynold’s Number , Re=
2.
Prandlt’s Number, Pr =
3.
Nusselt’s Number , Nu=
4.
Stanton’s Number ,
= = =
For natural convection h=f(gβ∆T,ρ,u,K,Cp,Lc) 1.
Grashof’s Number , Gr=
2.
Prandlt’s Number, Pr =
5.
Nusselt’s Number , Nu=
6.
Rayleigh’s Number ,
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