Aerodynamic enhancement of solar chimney airflow by an outlet-mounted NACA airfoil

Abstract

This study experimentally investigates the aerodynamic response of a laboratory-scale, wind-assisted solar chimney fitted with a NACA airfoil above its outlet. Thermal forcing was excluded to isolate wind–airfoil interactions. A Taguchi L25 orthogonal array assessed the effects of wind velocity, horizontal displacement, vertical stand-off distance, and airfoil angle on average chimney velocity, while ANOVA quantified factor contributions. The highest L25 response was 4.0675 m s−1 at 10 m s−1, +10 mm, 40 mm, and +10°, with triplicate validation yielding 4.070 ± 0.191 m s−1 (U95, k = 2). Taguchi main-effects analysis identified favourable levels of 10 m s−1, 0 mm, 50 mm, and +10° and ranked factor influence as wind velocity > airfoil angle > horizontal displacement > vertical distance. ANOVA showed that airfoil angle and wind velocity dominated the response, contributing 37.43% and 31.20%, respectively. These findings demonstrate that chimney airflow is highly sensitive to the outlet-airfoil configuration under controlled aerodynamic conditions.