Effects of Geometric Parameters for Wavy Finned-Tube Heat Exchanger in Turbulent Flow: A CFD Modeling

Abstract

In this study, the effects of thermal and hydraulic characteristics of wavy fin and tube heat exchanger are investigated. Simulation has been carried out by a commercial computational fluid dynamics code, ANSYS CFX12.0. The main objective of this study is to investigate the flow characteristics in turbulent flow. Results are predicted for the turbulent flow regime (2100≤Re≤7000) and compared with author's previous work for laminar (400 ≤Re≤1200) and transitional (1300≤Re≤2000) flow regime. Regarding turbulence, the k-ω model was used to predict the turbulent flow characteristics with 5% turbulence intensity. Predicted results were compared with the experimental data for the purpose of validation and the discrepancy is found within 10% in error range. Parametric study was conducted for different pitches and wavy angles. Flow characteristics obtained for the turbulent range is in line with the pattern observed in laminar and transitional ranges. This study demonstrates a clear understanding and relationship of among different flow ranges and the effects of different geometric parameters on the performance of heat exchanger.

Heat and mass transfer processes at high-temperature media during combustion of low-grade pulverized coal

“…Following shown results of three-dimensional modeling of heat and mass transfer processes during combustion of pulverized low-grade coal in real conditions of combustion chamber of boiler. Aerodynamic pattern of motion of two-phase turbulent flow of pulverized coal combustion causes the heat and mass transfer process in general [28][29][30]. Figure 2 shows a two-dimensional graph of the full velocity vector, determined by the relationship:…”

The effect of using different types of nanoparticles on optimal design of fin and tube heat exchanger

“…Viscosity and thermal conductivity of three studied nanofluids are estimated as follows : where κ and d np are Boltzmann constant (1.381 × 10 −23 J/K) and average size of nanoparticle, respectively. It should be noted that the previous correlation is valid for ϕ in the range of 0.01–0.1 for Al 2 O 3 but 0.01–0.06 for SiO 2 and CuO .…”

“…In fact, density is assumed to be a linear function of PVC. Density and specific heat of studied nanoparticles are listed in Table 1 [7, [22][23][24][25][26][27][28][29][30][31][32] . Moreover, all the water (as a base fluid) thermophysical properties are considered temperature dependent and determined at the average of inlet and outlet tube side temperatures.…”

“…Viscosity and thermal conductivity of three studied nanofluids are estimated as follows [22][23][24][25][26][27][28][29][30][31][32] :…”

“…In addition, a review on the modeling of thermal performance of the finned tube heat exchangers was studied by Bhuiyan et al under different flow ranges [26] . A computational fluid dynamics modeling was presented by Bhuiyan et al to find the effects of geometric parameters for wavy finned tube heat exchanger in turbulent flow [27] . In another research done by Bhuiyan et al, a plate fin and tube heat exchanger modeling was carried out to calculate the effects of different parameters on the performance for turbulent flow regime [28] .…”