Compact Solar Air Heater: A Review

In this review work, a theoretical study of solar air heater is carried out by considering compact heat exchanger criteria into account. The present investigation comprises different performance parameters for a compact solar air heater. In this review work, Reynolds number is the only variable parameter which varies from 4000 to 18000. Stanton number (St), Stanton number ratio (St/St₀), Colburn factor (j), and area goodness factor (j/f) are considered as performance parameters. Stanton number ratio (St/St₀) is maximum for multi-V-shaped ribs with gaps. Colburn factor (j) value is highest for multi-V-shaped ribs with gaps. In the present investigation, goodness factor (j/f) is highest for circular protrusions organized in angular arc form. This study is beneficial for the researchers to conduct the experimental and theoretical investigation in order to search out the new roughness geometries to design compact solar air heater.