Applications of Metaheuristic Algorithms in Solar Air Heater Optimization: A Review of Recent Trends and Future Prospects

Table 2

Recent important publications on solar air heaters using the thermohydraulic performance principle (2016-2020).

S. no.	Author(s) and year(s)	Computational domain	Description of the solar air heater system (model 2D/3D+turbulence model, algorithm)	Thermohydraulic performance	Other important remarks	References
1.	Kumar and Kim (2016)	Multi-V-type perforated baffles	3D model (of the flow domain), ANSYS FLUENT 6.3.26, CFD, RNG - disturbance model, SIMPLE algorithm	The maximum baffle width was 5.0.	Reynolds number: 3000 to 10,000. The average Nusselt number rises while the average friction component reduces with the Reynolds number. The 3D CFD analysis showed a positive outcome, and the CFD model is highly recommended for the rectangular channel baffle shape analysis. The investigated system showed good numerical optimal results with the experimental data.	[86]
2.	Gawande et al. (2016)	Reverse L-shaped ribs	2D CFD analysis SAH duct, ANSYS FLUENT 14.1, CFD code, RNG - disturbance model, SIMPLE algorithm	It varied between 1.62 and 1.9.	Reynolds number: 3800 to 18,000. The increasing Reynolds number increases with the average Nusselt number. The average friction component decreases with the increasing Reynolds number. The CFD theory and analytical results compared favorably with experimental results.	[87]
3.	Gill et al. (2017)	Broken arc ribs in a rectangular duct	3D periodic geometries of the roughened duct, ANSYS Academic Research CFD 15, RNG - turbulence model	1.94 at maximum	Reynolds number: 2000 to 16,000. The Nusselt number, friction coefficient, and thermohydraulic efficiency were enhanced.	[88]
4.	Singh (2017)	Arched absorber plate using turbulators	2D CFD model with the plane, ANSYS FLUENT (v16.2), RNG - turbulence model, SIMPLE algorithm	The value was clearly illustrated in the figure.	Reynolds number: 3800 to 14,000. The Nusselt number significantly improved at a high Reynolds number above 10,000. The study concluded that the arched shape design of the SAH absorber plate remarkably enhanced overall efficiency.	[89]
5.	Thakur et al. (2017)	Novel hyperbolic rib geometry	2D CFD simulation, ANSYS FLUENT 15.0 CFD code, RNG - model, SIMPLE algorithm	The value was clearly illustrated in the figure.	At a very high Reynolds number, the heat transfer rate was more noticeable in rectangular ribs than the pressure drop effect, which causes an overall increase in thermohydraulic performance.	[90]
6.	Gawande et al. (2018)	Various rib shapes (slanting, right-angled triangular, and reverse L-shaped ribs)	2D roughened computational domain SAH, ANSYS FLUENT 14.5 CFD code, RNG - model, SIMPLE algorithm	20° chamfered: from 1.577 to 2.047; Right-angled triangular rib: from 1.41 to 2.03; Reverse L-shaped rib: from 1.62 to 1.90	Reynolds number: 3800 to 18,000. The obtained values in the thermohydraulic performance column were achieved under the following conditions: 15,000 Reynolds number and 0.042 relative roughness height. In brief, it was clear that the specific thermal efficiency incremented in ascending order from the 20° slanted rib to the right-angled triangular rib and reverse L-shaped rib.	[91]
7.	Kumar and Layek (2018)	Absorber plate twisted rib	A duct with dimensions of was constructed from plywood.	2.13	Reynolds number: 3500 to 21,000. The optimum thermohydraulic performance of 2.13 was obtained at 21,000 Reynolds number.	[92]
8.	Manjunath et al. (2018)	Sinusoidal corrugations on the absorber plate	3D CFD simulation, SST - turbulence model, SIMPLE segregated solver	The metric was clearly illustrated in the figure.	Reynolds number: 4000 to 24,000. The thermohydraulic performance of all configurations exhibits higher values when compared to the previous base model. This was obtained by lower flow rate conditions. This study finally revealed that the SAH thermohydraulic performance is significantly influenced by the aspect ratio and wavelength of the sine wave corrugated absorber plate.	[93]
9.	Patel and Lanjewar (2018)	Staggered rib roughness combined with multiple discrete V-designs	The rectangular duct of flow cross-section.	1.55 at maximum	Reynolds number: 3000 to 12,000. The staggered rib combined with multiple discrete V-designs had greatly improved thermal efficiency.	[94]
10.	Menni et al. (2019)	Plane rectangular combined V-shaped floor channel SAH having various ribs	CFD software FLUENT, - disturbance model, Finite Volume Method (FVM), Standard -epsilon turbulence model (-), SIMPLE algorithm	The metric was clearly illustrated in the figure.	Reynolds number: 12,000 to 32,000. Among the various ribs (equilateral-triangular, trapezoidal, triangular pointing downstream, triangular pointing upstream, and square), the triangular pointing downstream was the optimal operating system. The ribs of the lower surface of the upper hot wall greatly increase the internal heat transfer efficiency of the channel.	[95]
11.	Bezbaruah et al. (2019)	Modified forms of conical vortex generators	3D model, ANSYS FLUENT 18.0, a commercial CFD tool, 5 turbulence models (ideal -, recognizable -, RNG -, SST -, and ideal - design), SIMPLE algorithm	1.06 at maximum	Reynolds number: 3000 to 15,000. This study revealed that the maximum 1.06 thermohydraulic performance was for half-canonical vortex generators at 60° attack angle and 1.02 for canonical vortex generators.	[96]
12.	Sivakandhan et al. (2020)	Inclined rib roughness	A mathematical model was developed by authors.	The value was clearly illustrated in the figure.	The study analytically improved the thermohydraulic performance of a new hybrid duct SAH. The results showed that the analyzed system highly improved the thermal and effective (thermohydraulic) efficiencies past 22.4% and 18.1%, respectively, when correlated with the traditional parallel pass rectangular duct solar air heater.	[97]
13.	Bensaci et al. (2020)	Different baffle positions	3D geometry, a numerical model based on CFD, ANSYS FLUENT 15.0, classical turbulence - models (ideal -, RNG -, recognizable -, and - designs), SIMPLE numerical algorithm	0.75 at maximum	Reynolds number: 2370 to 8340. This study discussed and analyzed the performance of four cases of different baffle positions. Then, the second case where baffles are located in the first half of the air channel (50 percent down) was recommended as the optimum configuration. After their CFD analysis, the RNG - disturbance prototype was also selected for its qualitative agreement and good accord with Dittus-Boelter and modified Blasius correlations.	[79]
14.	Dezan et al. (2020)	Irregular rows of rectangular winglet pairs	The flow was three-dimensional, ANSYS FLUENT 19.1 commercial code, - SST turbulence model	The value was clearly illustrated in the figure.	Reynolds number: 5000 to 10,000. The thermohydraulic efficiency of a SAH duct among rectangular winglet pairs was investigated. Thus, in all cases investigated, the study revealed that the thermohydraulic efficiency that was not systematically mounted on the channel exceeded those of fixed interval plans.	[98]
15.	Nidhul et al. (2020)	V-ribs	3D CFD simulation, ANSYS v19.0, RNG - turbulence model, SIMPLE algorithm	2.01 at maximum	Reynolds number: 5000 to 20,000. This study used the CFD and exergy analysis of triangular duct V-rib SAH applying the given Reynolds number. The new SAH architecture improves the overall performance when compared to other artificial roughness employed in the triangular duct solar air heaters.	[99]