Experimental and Computational Study of Beef Grilling in a Steak Grill

This research investigated the natural convection and hot gas flow behavior inside a commercial steak grill using both experimental measurements and computational fluid dynamics (CFD) simulations. Real operating data on gas and air usage were collected to build a realistic domain of the grill and to simulate the combustion process inside the grill. Temperature distributions inside the empty grill were measured using 17 thermocouples placed at various points, including air and gas inlet and outlet locations. These measurements were divided into three distinct height levels, with five temperature measurement points at each level. Additionally, a virtual steak grilling simulation was performed using CFD, incorporating meat properties such as density, thermal conductivity, and heat capacity, all of which varied with temperature. This approach provided a more accurate prediction of heat transfer from the hot gas to the steak, offering valuable insights into the actual grilling process inside the gas-fired steak grill. The experimental results revealed that the lowest level, particularly at the center of the grill, consistently showed the highest temperature, while temperatures near the edges were significantly lower (with a maximum temperature difference of ∆T ≈ 45°C). The CFD simulation results supported the experimental findings and identified the root cause of the uneven temperature distribution, which originated from the original structural design of the grill. After analyzing and modifying the internal design, perforated metal plates were installed to guide the hot gas flow, which improved temperature uniformity. This modification reduced the temperature variation across the grill surface to approximately 10°C, improving heat distribution and ensuring more consistent steak quality while reducing grilling time.