Technical education in Nigerian polytechnics is constrained by inadequate workshops equipment, high importation costs of machines, and limited practical training opportunities, resulting in graduates with insufficient hands-on skills especially in metallurgy and casting. This study completed the design and numerical simulation of a rotary melting furnace specifically developed for practical demonstration in the foundry workshop of the Department of Mechanical Engineering Technology, Federal Polytechnic Mubi. The furnace features a horizontal mild-steel cylindrical shell of 900 mm diameter and 1,500 mm length, lined with 150–200 mm high-alumina refractory, supported on riding rings and rollers, and driven at 1–5 rpm by an electric motor and gearbox. A furnace-oil burner is mounted on a movable charging door. The design process combined conventional mechanical design principles, three-dimensional CAD modelling, and computational fluid dynamics (CFD) simulation to evaluate thermal performance before fabrication. Simulation results showed that the furnace reaches flame-zone temperatures of 1,450–1,550 °C and charge temperatures of 1,250–1,380 °C, sufficient for melting cast iron and aluminium alloys. A rotational speed of 2–3 rpm produced the best balance of temperature uniformity (maximum difference 35–70 °C) and melting time (70–90 minutes for a 250 kg charge). Overall thermal efficiency ranged from 42 % to 55 %, while outer-shell temperatures remained safely below 180 °C. The completed design demonstrates that a functional, educationally oriented rotary furnace can be developed using locally available materials and modern simulation tools. Once fabricated, the furnace will enhance student practical skills, promote institutional self-reliance, and reduce dependence on expensive imported equipment.