Hi.
These questions are for those, who are familiar with Nusselt number correlations and PHE research history.
Q1:
Rosenblad and Kullendorff (1) had j[sub]D[/sub]=0.273 x Re[sup]-0.303[/sup] for the correlation in their experiment. But Manglik (2) proposed Nu=0.289 x Re[sup]0.697[/sup] x Pr[sup](1/3)[/sup] for the correlation according to Rosenblad and Kullendorff (1).
I don't understand why the coefficient 0.273 from the original experiment has changed to 0.289? And where did the Pr[sup](1/3)[/sup] come from since Rosenblad and Kullendorff didn't mention it in their original experiment?
Q2:
Heavner and Kumar (3) formulated correlations for different chevron angles. For example
β[sub]avg[/sub] 22.5° j[sub]Nu[/sub]=0.278 x Re[sup]0.683[/sup]
but according to Manglik (2), the correlation is Nu=0.278 x φ[sup]0.317[/sup] x Re[sup]0.683[/sup]. So where did the enlargement factor φ[sup]0.317[/sup]come from?
1 Rosenblad, G., Kullendorff, A. 1975. Estimating Heat Transfer Rates from Mass Transfer Studies on Plate Heat Exchanger Surfaces. Wärme- und Stoffübertragung. Vol. (8), p. 187-191. Springer-Verlag.
2 Manglik, R.M. 1996. Plate heat exchangers for process industry applications: enchanced thermal-hydraulic characteristics of chevron plates. Process, Enhanced and Multiphase Heat Transfer, p. 267-276. Begell House.
3 Heavner, R.L., Kumar, H., Wanniarachchi, A.S. 1993. Performance of an Industrial Plate Heat Exchanger: Effect of Chevron Angle. AIChE Symposium Series. Vol. 89 (295), p. 262-267.
These questions are for those, who are familiar with Nusselt number correlations and PHE research history.
Q1:
Rosenblad and Kullendorff (1) had j[sub]D[/sub]=0.273 x Re[sup]-0.303[/sup] for the correlation in their experiment. But Manglik (2) proposed Nu=0.289 x Re[sup]0.697[/sup] x Pr[sup](1/3)[/sup] for the correlation according to Rosenblad and Kullendorff (1).
I don't understand why the coefficient 0.273 from the original experiment has changed to 0.289? And where did the Pr[sup](1/3)[/sup] come from since Rosenblad and Kullendorff didn't mention it in their original experiment?
Q2:
Heavner and Kumar (3) formulated correlations for different chevron angles. For example
β[sub]avg[/sub] 22.5° j[sub]Nu[/sub]=0.278 x Re[sup]0.683[/sup]
but according to Manglik (2), the correlation is Nu=0.278 x φ[sup]0.317[/sup] x Re[sup]0.683[/sup]. So where did the enlargement factor φ[sup]0.317[/sup]come from?
1 Rosenblad, G., Kullendorff, A. 1975. Estimating Heat Transfer Rates from Mass Transfer Studies on Plate Heat Exchanger Surfaces. Wärme- und Stoffübertragung. Vol. (8), p. 187-191. Springer-Verlag.
2 Manglik, R.M. 1996. Plate heat exchangers for process industry applications: enchanced thermal-hydraulic characteristics of chevron plates. Process, Enhanced and Multiphase Heat Transfer, p. 267-276. Begell House.
3 Heavner, R.L., Kumar, H., Wanniarachchi, A.S. 1993. Performance of an Industrial Plate Heat Exchanger: Effect of Chevron Angle. AIChE Symposium Series. Vol. 89 (295), p. 262-267.
