Solar air heaters are widely used in various household and industrial applications. Reduced thermal efficiency of solar air heaters has necessitated the researchers to focus on the improvement of the thermal performance by providing artificial flow modification techniques in the flow field. As a result of this, laminar sublayer beneath the absorber plate will get disturbed and this helps to increase the turbulence level of the air. This results in increased heat transfer rate from the absorber plate. Paper discusses the influence of different shaped turbulators used by the various researchers in improving the thermal performance of air heaters. Design considerations, geometries used, flow conditions and their influence on turbulence, heat transfer rate, absorber temperature and thermo-hydraulic enhancement factor have been thoroughly discussed. Finally concluding remarks and the future scope for additional enhancement in the performance of solar air heater is proposed.

太阳能空气加热器广泛用于各种家庭和工业应用中。太阳能空气加热器的热效率降低，已使研究人员必须通过在流场中提供人工流量调节技术来集中精力改善热性能。结果，吸收板下方的层状子层将受到干扰，这有助于增加空气的湍流度。这导致吸收板的传热速率增加。论文讨论了各种研究人员使用的不同形状的湍流器对改善空气加热器的热性能的影响。设计方面的考虑因素，所使用的几何形状，流动条件及其对湍流，传热速率，吸收塔温度和热工水力增强因子的影响已进行了全面讨论。