Najeeb Shehab S. INVESTIGATION THE EFFECT OF ASPECT RATIO ON THE FREE HEAT CONVECTIVE INSIDE A HORIZONTAL HEATED TUBE. J. eng. sustain. dev. 2017;21(3):119-135. Accessed March 16, 2025. https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/539