THEORATICAL AND EXPERIMENTAL ANALYSIS OF SOLAR AIR HEATER WITH W-SHAPED ROUGHNESS ON ABSORBER PLATE. International Engineering Journal For Research & Development, [S. l.], v. 4, n. 7, p. 9, 2019. Disponível em: https://iejrd.com/index.php/iejrd/article/view/433. Acesso em: 16 apr. 2026.