Thermal Performance Enhancement of Solar Air Heaters Using Multi-V-Shaped Perforated Ribs With Different Directions. Al-Rafidain Engineering Journal (AREJ), [S. l.], v. 31, n. 1, p. 34–48, 2026. DOI: 10.33899/arej.v31i1.61936. Disponível em: https://rengj.uomosul.edu.iq/index.php/rengj/article/view/61936. Acesso em: 22 jul. 2026.