Journal of Solar Energy

Research Article

Performance Evaluation Criterion at Equal Pumping Power for Enhanced Performance Heat Transfer Surfaces

Table 1

Performance ratio equations.
InvestigatorsPerformance ratioConstraintsConditions to be fulfilled
Multi-tube Exchangers
Webb and Eckert [2](St/ )/( / )1/3 = , = , and = ,
, and 		> , > , < ,     
= ( / ) ,  
/ = / = /Re = ( / )1/3,
  = ( / )1/3 Re
Present authorsNu/ (= / ) = , = , and = ,
, and 		> , > , < ,   
= ( / ) ,
/ = / = /Re = ( / )1/3, 
= ( / )1/3 Re
Present authors(St/ )/( / )1/3,   
(Nu/ )/( / )1/3,
or / 		= , = , = , and
= Re, , 		> , < , > ,
/ = ( / )1/3 = / = /
Bergles et al. [3] / or /     
( / = Nu/ )		 = , = , = , and
= , 		> , > ,   
/ = /Re,  
= ( / )1/3 Re
Rectangular Duct
Liou and Hwang [36]Nu/ = / , = , = ,
= , and = 		> , > ,
/ = /Re,
= ( / )1/3 Re
Present authors / ,
(Nu/ )/( / )1/3,   
or (St/ )/( / )1/3		High aspect ratio duct
( ≫ ): = , = , , and = 		> , < , = ,
= ( / )1/3,
Re = 2 /( )
The parameters with asterisk (*) are to be evaluated at the Reynolds number defined in column 4.