CFD analysis of novel two-pass, sinusoidal corrugated, trapezoidal channel for solar air heater

Abstract

Solar is regarded as a clean and reliable source of energy. Solar air heaters (SAHs) are one of the most prevalent applications of solar energy. SAHs have normally low thermal efficiency. In order to increase thermal efficiency, a sinusoidal wave corrugation is employed on the base wall of the twin-pass channel of an absorbent plate with a sharp bend. A parametric study was conducted to study the effect of flow and geometric parameters i.e. wave height, pitch, and propagation angle of the wave with respect to flow inlet on performance parameters. Computational Fluid Dynamics (CFD) tool was implemented to examine the performance parameters i.e. heat transfer enhancement, pressure drop, and thermal performance factor. In comparison to the orthogonal ones, inclined corrugation is more efficient in terms of heat transfer. With the increase in roughness height, pitch, and corrugation angle, an increasing trend was observed in Thermal Performance Factor, followed by a diminishing trend. The corrugated channel having a roughness height ratio of 19, two waves in a single block with a 45° wave propagation angle seemed to be an optimal configuration with 35% enhancement in thermal performance factor as compared to the smooth channel, hence representing promising augmentation.

KEYWORDS:

• Solar Air Heaters (SAH)
• two-pass trapezoidal channel
• sinusoidal corrugation
• computational fluid dynamics
• heat transfer enhancement
• thermal performance factor

Acknowledgement

The authors acknowledge the computational support by the Advance Computational Research Laboratory (ACRE), Department of Nuclear Engineering, Pakistan Institute of Engineering and Applied Sciences, Pakistan

Disclosure statement

No potential conflict of interest was reported by the author(s).