Kassem, Mahmoud A. <br/><br/>
Performance evaluation of swirl flow solar air heater  [electronic resource]. 
 تقييم أداء سخان الهواء الشمسى ذو السريان الدوامى. 

 - p.1429- 1446. 
<br/><br/>Includes references. 
<br/><br/> The objective of the present study is to evaluate the performance of a new design of solar air heater. In the new design, the air is swirled by using twisted-tape insert in the air passage. Initially, the heat transfer and pressure drop for swirled flow has been tested in order to identify the optimum tape twist ratio which satisfies a maximum heat transfer coefficient, with accepted value of air pressure drop.  The proposed air heater was compared with the conventional air heater under the same operating conditions. The results show that the proposed air heater is superior - instantaneous and daily bases- in energy output, efficiency and exit-air temperature. 
<br/><br/><br/>Summary in Arabic. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Solar heating.<br/>Solar energy--Research.<br/>Air heaters.