Effect of packing in the airflow passage on the performance of a solar air-heater with conical concentrator

It was found that the airside heat transfer coefficient has been about 26 W/m2 K for empty airflow passage of the absorbing tube. By using aluminium wire mesh packing, the heat transfer coefficient increased regularly with increasing number of folds of the wire mesh packing and reached to 240 W/m2 K in the case of 14 folds.