Journal of Wind Engineering and Industrial Aerodynamics, 15 (1983) 65--76 65 Elsevier Science Publishers B.V., Amsterdam -- Printed in The Netherlands COMPARISON OF SIMULATED AND FULL-SCALE WIND STRUCTURE OVER A SMALL SUBURBAN AIRPORT R.G.J. FLAY L and H.W. TEUNISSEN 2 IDSS~ International Inc., Toronto, Canada 2Atmospheric Environment Service, Toronto, Canada SUMMARY The paper describes wind-tunnel measurements of the flow over a l:1920-scale topo- graphic model of a small suburban airport near Ottawa, Ontario and compares them with full-scale measurements. The wind-tunnel measurements were carried out in the AES Boundary-Layer Wind Tunnel. The model approach flow is compared with the desired target flow characteristics and with full-scale results. Wind-structure measurements obtained at the equivalent locations of the instruments in the full-scale flow are compared with the corresponding full-scale results. The measurements include mean velocity and turbulence profiles, auto- and cross-correlations, power spectra and length scales. The simulated flow agreed well with the prototype flow for most parameters. However, at very low levels the mean velocity in the simulation was less than in full scale. The wind-tunnel flow was also less energetic in the lateral directions com- pared with the full-scale flow, i.e. there was a lack of large-scale, low-frequency eddies in the lateral directions. The relatively good agreement between the simulated and prototype flows indicates that good simulations are possible at geometric scales as small as 1:2000 providing one is not interested in the flow very close to the model surface. In many cases the lack of energy in the lateral directions will not be important. i. INTRODUCTION The use of topographic or "terrain-simulation" models of full-scale terrain is a fairly common practice in most boundary-layer wind tunnel facilities. Such models are aimed at reproducing the structure of the mean winds and turbulence which occurs in the prototype atmospheric boundary-layer flow over the terrain in question. The length scale of these models is of course determined by the size of the area to be modelled and the dimensions of the wind tunnel and can range typically from 1:500 to 1:5000 or more. At the smaller scales, the surface features in the model become extremely small, and the question arises as to how well the full-scale flow is actually simulated in the wind tunnel. In general, there have been very few full-scale/model comparisons aimed directly at assessing the faithfulness with which the full-scale boundary-layer flow is reproduced by topographic models in the wind tunnel. Perhaps the primary reason for this is the relatively high cost and difficulty of obtaining adequate full-scale data for compari- son with wind-tunnel results. One of the more comprehensive efforts to date is that carried out by Meroney et al [i] involving a 1:5000 model of the Rakaia Gorge area in New Zealand. The report on this work provides an excellent sumnlary of most of the 0167-6105/83/$03.00 © 1983 Elsevier Science Publishers B.V.