0012 and CLARK Y (2D wing-segment models with typical airfoils), AGARD-B / AGARD-C (generic delta-wing-airplane shapes), ONERA-M (a generic transport-airplane shape), HB-2 (Hypervelocity ballistic model 2, a shape similar to a reentry-body). For dynamic tests, the often-used standard models are: SDM (Standard dynamic model, a generic fighter-like airplane shape somewhat similar to F-16)), BFM (Basic finner model, a generic conical-cylindrical missile with four fins at the rear end) and MBFM (Modified basic finner model). A number of other standard models exists as well. With the increased use of wind tunnels in the testing of road vehicles, several standard models of generic car shapes were defined., such as the Ahmed body , MIRA reference car , etc. Some wind tunnel laboratories perform periodical checkouts using internally defined standard models that are selected from the repository of models previously tested in the facility Geometry of a standard wind tunnel model is defined relative to some easily identified parameter (see figure), e.g. body diameter or wing chord. The geometry is published by the institution proposing the model. Beside the model itself, a standard model support, such as a sting, to be used with the model, is usually defined. An actual model is built to a size suitable for the size of a specific wind tunnel test section, in particular taking care that the frontal blockage of the model (the ratio of the model cross-section area to wind tunnel test section area) is kept well below 1% (except for wall-interference research where the models may be larger). In order to eliminate the effects of production differences between models in inter-facility comparisons, sometimes the same physical standard model is tested in several wind tunnels See also Wind tunnel AGARD-B wind tunnel model References External links Wind tunnels Physical models