When performing the circulating water channel testing of a submerged body, some form of mounting device is inevitably required to maintain the object of interest in a stationary position as the water is circulated around it. However, these devices disturb the local flow field and therefore result in measurement errors. Although various experimental guidelines and compensation schemes have been proposed for minimizing the flow interference effects of these devices, the experimental errors which they induce are still not yet fully understood. Accordingly, the present study performs a series of numerical investigations to examine the effects of two typical mounting devices, namely a vertical rod-like suspension bracket and a flat horizontal stand, on the flow fields induced around two submerged bodies, i.e. a torpedo-like body and an artificial reef block, respectively. The numerical results provide valuable insights into the flow interference effects of the two mounting devices and allow the likely experimental errors to be estimated in both cases.
The hydrodynamic and cavitation properties of an object are commonly evaluated by placing the object in a water tunnel and then using some form of visualization technique to observe the resulting flow phenomena as the water is circulated around it. Such tests enable the force, moment and pressure acting on the object to be reliably measured and allow various properties of the flow field around the model, most notably the local velocity, to be evaluated with a high degree of precision. The results obtained from such hydrodynamic tests provide a useful means of verifying the data obtained from theoretical or numerical analyses and provide an invaluable source of information to facilitate both the design of the submerged object itself and that of suitable experimental procedures with which to evaluate its hydrodynamic performance.
