A new geometry of roughness in the sinusoidal form has been investigated computationally using Computational Fluid Dynamics (CFD) software for examining the influence of roughness on heat transfer and fluid friction in solar air heater and results obtained have been compared with experimental results. The simulated results for smooth solar air heater are compared with Dittus-Boelter equation for heat transfer and Blasius equation for fluid friction. The deviation of simulated results are found to be 7.55% and 16.91%, respectively. In order to validate the simulated results experimental test rig was fabricated and experiments were carried out for the same set of parameters used in the simulation. The experimental results indicate that for the roughened absorber plate having a sinusoidal rib, the variation in heat transfer is within 9% from that of simulated results and for fluid friction, deviation is within 4%. The optimal value of thermohydraulic performance (THP) is obtained 2.05 for roughness pitch (P) = 10 mm and Reynolds number (Re) = 4000, where enhancement ratio of Nusselt number (Nu_r/Nu_s) and friction factor (ƒ_r/ƒ_s) are 2.48 and 1.76, respectively. The experimental value of THP is found to be within 6.77% of the value indicated by CFD analysis. The results are also compared with the triangular and square rib and found that the optimal THP of the proposed rib is 20.06% and 33.31% more.

已使用计算流体动力学（CFD）软件通过计算研究了正弦形式的粗糙度的新几何形状，以检查粗糙度对太阳能空气加热器传热和流体摩擦的影响，并将所得结果与实验结果进行了比较。将光滑太阳能空气加热器的模拟结果与Dittus-Boelter方程进行传热和Blasius方程进行流体摩擦的比较。模拟结果的偏差分别为7.55％和16.91％。为了验证仿真结果，制造了实验测试台，并针对仿真中使用的同一组参数进行了实验。实验结果表明，对于具有正弦肋的粗糙吸收板，传热的变化与模拟结果相差不超过9％，对于流体摩擦，偏差不超过4％。当粗糙度螺距（P）= 10 mm和雷诺数（Re）= 4000时，热液压性能（THP）的最佳值是2.05，其中努塞尔特数（Nu_[R /女_小号）和摩擦系数（ƒ _{- [R} /ƒ_小号）分别是2.48和1.76。发现THP的实验值在CFD分析指示的值的6.77％之内。将结果与三角形和正方形肋骨进行比较，发现所建议肋骨的最佳THP分别为20.06％和33.31％。