TY - JOUR
T1 - Empirical correlations development for heat transfer and friction factor of a solar rectangular air passage with spherical-shaped turbulence promoters
AU - Maithani, Rajesh
AU - Kumar, Anil
AU - Gholamali Zadeh, Peyman
AU - Safaei, Mohammad Reza
AU - Gholamalizadeh, Ehsan
N1 - Publisher Copyright:
© 2019, Akadémiai Kiadó, Budapest, Hungary.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - A study was conducted to enhance the thermo-hydraulic performance of a rectangular solar air passage with integrated spherical-shaped turbulence promoters. The effects of the flow and geometric parameters on heat transfer along with the friction factor were studied. The experiments were carried out with a relevant range of the Reynolds number from 4500 to 16,500, and geometric parameters consisting of the dimensionless spherical-shaped diameter (Ds/ DH) from 0.130 to 0.217, the stream-wise spacing parameter (Xs/ Ds) from 4.04 to 6.47 and the span-wise spacing parameter (Ys/ Ds) from 4.04 to 6.47. An analysis was further carried out to develop empirical correlations for the Nusselt number and the friction factor in terms of geometric parameters and the Reynolds number. Comparisons between results of correlations and the experimental data revealed good agreements. Results showed that, at a specific Reynolds number, the Nusselt number reached a peak at Ds/ DH and Ys/ Ds of 0.195 and 4.62, respectively. An increase in the value of Ds/ DH increases the friction factor, while an increase in (Xs/ Ds) and Ys/ Ds decreased the friction factor. Maximum friction factor for Ds/ DH, (Xs/ Ds) and Ys/ Ds was found at 0.217, 4.04 and 4.04, respectively. In addition, to evaluate the thermo-hydraulic performance, an efficiency parameter called the efficiency factor was calculated. The maximum value of the efficiency factor was 2.98, which occurred at the Reynolds number of 10,500 corresponding to the optimal parameters Ds/ DH = 0.195, Xs/ Ds = 4.04, and Ys/ Ds = 4.62.
AB - A study was conducted to enhance the thermo-hydraulic performance of a rectangular solar air passage with integrated spherical-shaped turbulence promoters. The effects of the flow and geometric parameters on heat transfer along with the friction factor were studied. The experiments were carried out with a relevant range of the Reynolds number from 4500 to 16,500, and geometric parameters consisting of the dimensionless spherical-shaped diameter (Ds/ DH) from 0.130 to 0.217, the stream-wise spacing parameter (Xs/ Ds) from 4.04 to 6.47 and the span-wise spacing parameter (Ys/ Ds) from 4.04 to 6.47. An analysis was further carried out to develop empirical correlations for the Nusselt number and the friction factor in terms of geometric parameters and the Reynolds number. Comparisons between results of correlations and the experimental data revealed good agreements. Results showed that, at a specific Reynolds number, the Nusselt number reached a peak at Ds/ DH and Ys/ Ds of 0.195 and 4.62, respectively. An increase in the value of Ds/ DH increases the friction factor, while an increase in (Xs/ Ds) and Ys/ Ds decreased the friction factor. Maximum friction factor for Ds/ DH, (Xs/ Ds) and Ys/ Ds was found at 0.217, 4.04 and 4.04, respectively. In addition, to evaluate the thermo-hydraulic performance, an efficiency parameter called the efficiency factor was calculated. The maximum value of the efficiency factor was 2.98, which occurred at the Reynolds number of 10,500 corresponding to the optimal parameters Ds/ DH = 0.195, Xs/ Ds = 4.04, and Ys/ Ds = 4.62.
KW - Heat transfer
KW - Solar air passage
KW - Spherical-shaped turbulence promoters
KW - Thermo-hydraulic performance
UR - http://www.scopus.com/inward/record.url?scp=85068995828&partnerID=8YFLogxK
U2 - 10.1007/s10973-019-08551-8
DO - 10.1007/s10973-019-08551-8
M3 - Article
AN - SCOPUS:85068995828
SN - 1388-6150
VL - 139
SP - 1195
EP - 1212
JO - Journal of Thermal Analysis and Calorimetry
JF - Journal of Thermal Analysis and Calorimetry
IS - 2
ER -