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Numerical Heat Transfer, Part A: Applications
An International Journal of Computation and Methodology
Volume 75, 2019 - Issue 1
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Articles

Heat transfer and pressure drop correlations for laminar flow in an in-line and staggered array of circular cylinders

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Pages 1-20 | Received 17 Sep 2018, Accepted 19 Dec 2018, Published online: 01 Mar 2019

Figures & data

Figure 1. Concept of a flat tube heat exchanger with plate-fin wire structure.

Figure 1. Concept of a flat tube heat exchanger with plate-fin wire structure.

Figure 2. Different wire structure heat exchangers with high aspect ratio tested for thermal–hydraulic performance: (a) continuous wire structure; (b) pin fin structure; and (c) woven wire structure (adopted from [Citation18,Citation21,Citation22]).

Figure 2. Different wire structure heat exchangers with high aspect ratio tested for thermal–hydraulic performance: (a) continuous wire structure; (b) pin fin structure; and (c) woven wire structure (adopted from [Citation18,Citation21,Citation22]).

Figure 3. Cross-section through a wire structure heat exchanger.

Figure 3. Cross-section through a wire structure heat exchanger.

Figure 4. Boundary conditions of the in-line (a) and staggered (b) cross-section model [Citation18].

Figure 4. Boundary conditions of the in-line (a) and staggered (b) cross-section model [Citation18].

Table 1. Definition of nondimensional input parameters to simulation model with minimal and maximal values in parametric study.

Figure 5. Meshing of 2D cross-section with different levels of grid refinement.

Figure 5. Meshing of 2D cross-section with different levels of grid refinement.

Table 2. Grid Convergence Index (GCI) based on Richardson method [Citation27] for Nusselt number and friction factor.

Figure 6. Pressure difference, velocity, and temperature of a 2D in-line wire structure simulation with a = 10, b = 3, Rest = 20, and nwires=20. Contour lines for pressure difference are equally distributed. Velocity streamlines are colored based on the temperature scale.

Figure 6. Pressure difference, velocity, and temperature of a 2D in-line wire structure simulation with a = 10, b = 3, Rest = 20, and nwires=20. Contour lines for pressure difference are equally distributed. Velocity streamlines are colored based on the temperature scale.

Figure 7. Nusselt number and Fanning friction factor of an in-line wire structure for a developed flow as a function of Reynolds number and geometry parameters a and b.

Figure 7. Nusselt number and Fanning friction factor of an in-line wire structure for a developed flow as a function of Reynolds number and geometry parameters a and b.

Figure 8. Correlated global (solid line) and local (dashed line) Nusselt number, Nust and Nust,local, respectively, for an in-line wire arrangement, as a function of the number of wires based on the simulated global data points (squares) for Nust and fixed values for a=10,b=3,Rest=20. Downstream of the thermal entrance length (dotted line), the flow is declared as thermally developed.

Figure 8. Correlated global (solid line) and local (dashed line) Nusselt number, Nust and Nust,local, respectively, for an in-line wire arrangement, as a function of the number of wires based on the simulated global data points (squares) for Nust and fixed values for a=10,b=3,Rest=20. Downstream of the thermal entrance length (dotted line), the flow is declared as thermally developed.

Figure 9. Correlated global (solid line) and local (dashed line) friction factor, fst and fst,local, respectively, for an in-line wire arrangement as a function of the number of wires based on the simulated global data points (squares) for fst and fixed values for a=10,b=3,Rest=20. Downstream of hydraulic entrance length (dotted line), the flow is declared as hydraulically developed; in-line arrangement.

Figure 9. Correlated global (solid line) and local (dashed line) friction factor, fst and fst,local, respectively, for an in-line wire arrangement as a function of the number of wires based on the simulated global data points (squares) for fst and fixed values for a=10,b=3,Rest=20. Downstream of hydraulic entrance length (dotted line), the flow is declared as hydraulically developed; in-line arrangement.

Figure 10. Predicted (correlated) values versus simulated values for (a) the Nusselt number Nust,y* and (b) the Fanning friction factor fst,y*. Data are based on EquationEqs. (13) and Equation(19). The predicted values are correlated via the number of wires nwires (see ) for specific Reynolds numbers Rest and geometry parameters a and b for an in-line arrangement.

Figure 10. Predicted (correlated) values versus simulated values for (a) the Nusselt number Nust,y* and (b) the Fanning friction factor fst,y*. Data are based on EquationEqs. (13)(13) Nust,y*=Nust,∞+C1,NuC2,Nu(y*−1)1−y*−C2,Nu (13) and Equation(19)(19) fst,y*=fst,∞+C1,fC2,f(y*−1)1−y*−C2,f (19) . The predicted values are correlated via the number of wires nwires (see Table 1) for specific Reynolds numbers Rest and geometry parameters a and b for an in-line arrangement.

Table 3. Derived correlations for Nust, and fst, for an in-line wire structure.

Table 4. Derived correlations for coefficients of Nust and fst for in-line wire structure based on the EquationEqs. (13) and Equation(19).

Figure 11. Auxiliary coefficients A˜Nu (a), B˜Nu (b), A˜f (c), and B˜f (d) needed for calculation of correlated Nusselt number and friction factor based on for in-line arrangement. Geometry parameter a is shown on the contour lines.

Figure 11. Auxiliary coefficients A˜Nu (a), B˜Nu (b), A˜f (c), and B˜f (d) needed for calculation of correlated Nusselt number and friction factor based on Table 3 for in-line arrangement. Geometry parameter a is shown on the contour lines.

Figure 12. Nondimensional entrance lengths Lth* and Lhy* for an in-line arrangement based on the Reynolds number Rest and geometry parameters a and b. Entrances lengths below 0.1 are not shown.

Figure 12. Nondimensional entrance lengths Lth* and Lhy* for an in-line arrangement based on the Reynolds number Rest and geometry parameters a and b. Entrances lengths below 0.1 are not shown.

Figure 13. Predicted (correlated) values versus simulated values for (a) the Nusselt number Nust, and (b) the Fanning friction factor fst, for a developed flow. Data are based on . The predicted values are correlated via the Reynolds number Rest and geometry parameters a and b for an in-line wire arrangement.

Figure 13. Predicted (correlated) values versus simulated values for (a) the Nusselt number Nust,∞ and (b) the Fanning friction factor fst,∞ for a developed flow. Data are based on Table 3. The predicted values are correlated via the Reynolds number Rest and geometry parameters a and b for an in-line wire arrangement.

Figure 14. Predicted (correlated) values versus simulated values for (a) the Nusselt number Nust,y* and (b) the Fanning friction factor fst,y*. Data are based on EquationEqs. (13) and Equation(19) ( and ). The predicted values are correlated via the Reynolds number Rest, geometry parameters a and b, and the number of wires for an in-line wire arrangement.

Figure 14. Predicted (correlated) values versus simulated values for (a) the Nusselt number Nust,y* and (b) the Fanning friction factor fst,y*. Data are based on EquationEqs. (13)(13) Nust,y*=Nust,∞+C1,NuC2,Nu(y*−1)1−y*−C2,Nu (13) and Equation(19)(19) fst,y*=fst,∞+C1,fC2,f(y*−1)1−y*−C2,f (19) (Tables 3 and 4). The predicted values are correlated via the Reynolds number Rest, geometry parameters a and b, and the number of wires for an in-line wire arrangement.

Table 5. Percentage of correlated data which satisfy a relative residual error below 5% and 10% for Nust,, fst,, Nust,y*, and fst,y*.

Table B1. Predicted correlation for coefficients of Nust and fst for staggered wire structure based on the EquationEqs. (13) and Equation(19).

Table B2. Percentage of correlated data which satisfy a relative residual error below 5% and 10% for Nust,, fst,, Nust,y*, and fst,y* in staggered wire arrangement.