Abstract

The study of parameters selection of model sizing appropriate for use in an Eiffel type subsonic boundary layer wind tunnel was investigated. Using a prototype-model dimension scale of 1:300 on a 72 m, 20 storey prototype building with ratio 1:2:6; a width of 43.33, 83.33 mm breadth and 240 mm height was produced as physical model. The result of the application of methods of global modular ratio and area moment for parameters selection shows that the moments of inertia obtained from the two methods only differ by 2.33%. The proposed hollow rectangular configuration recommended as walls for the physical model are 10.5 and 20.2 mm thick along the width and breadth, respectively. The assemblage of the models was rigidly bounded together by using a set of G-clamping devices and special adhesives such as epoxy resin and liquid glue. The base of the physical model was mounted on flat steel plate which serves as an infinitely rigid foundation resting on the polystyrene that represents the soil conditions which was assumed to behave as elastic base. At the end, the model was rigidly fastened to the wind tunnel using solenoid wires. The original data generated for the dimensions were intrinsically linear and they were linearized using a natural logarithm model. Ordinary least square regression analysis conducted on the result show that y = 1.94 + 0.433x. The analysis of variance (ANOVA) is significant at P = 0.001 but the corresponding standard deviation, correlation coefficients and student’s T are S = 0.1561, R - Sq = 93.9% and T = 9.23, respectively. All these statistically confirm that there are no serious trends to show that the proposed models are inappropriate.

Key words: Model sizing, strouhal number, Bernoulli universal constant, wind tunnels, model scaling, multi-storey, building, aerodynamics loadings.