University of Al-Qadisiyah Al-Qadisiyah Journal for Engineering Sciences 1998-4456 3 1 2010 03 28 NUMERICAL SIMULATION OF NATURAL CONVECTION IN A LAMINAR TWO – DIMENSIONAL FLOW THROUGH A VERTICAL RECTANGULAR DUCT. المحاكاة العددية للحمل الحر لجريان طباقي ثنائي البعد خلال نفق عمودي مستطيل المقطع 51 63 32309 EN Journal Article 2010 03 01 This research uesd to compute the flow field variables of natural convection air flow based on finite difference computational fluid dynamic methods. The problem considered deals with a two-dimensional internal, laminer , isothermal flow over a vertical rectangular duct. In this work, governing equations were solved using finite different forward explicit technique. The flow characterstics are evaluated for Prandtl number at 0.7 and dimensionless inlet velocity equals to 0.005. The results explain that the heat transfer rate is a strong function of flow velocity also the hydrodynamic properties such as pressure, temperature and velocity are increased when the flow moves upward the duct.The results showed a good agreement with other published results. https://qjes.qu.edu.iq/article_32309_56c7f7435d8e6860ca392b2b06d5643f.pdf