Specifying the type, size, and position of turbulence stimulation devices for towing tank models can be a challenging endeavor. This is particularly true when testing small-scale models and/or models operating at low speeds. Presently, the guidance for test engineers comes primarily in the form of empirical relations provided in classic papers on the subject and from one’s own testing experience. In the present work, an alternative approach is investigated. Specifically, the use of the local Reynolds number based on the momentum thickness in the model hull boundary layer, Rn_, and the pressure gradient parameter, K, to guide the sizing and placement of turbulence stimulation devices is explored. This approach is common in wind tunnel transition studies, but to the authors’ knowledge, has not received a great deal of attention in the towing tank community. This is likely due to the difficulty in measuring these quantities in a towing tank. To avoid this issue, these parameters were calculated for the hull geometry of interest using simple, web-based computational fluid dynamics (CFD) codes. Experiments were carried out using models instrumented with flush-mounted hot-film anemometers. The output signals from the anemometers were analyzed and were able to detect the fraction of time that the boundary layer was turbulent, termed intermittency. Results from both a flat plate model and a wall-sided, two-dimensional model with streamwise curvature are presented and indicate that the present approach has merit. For example, the intermittency observed in the boundary layer correlates well with Rn_. Also, the effective ‘jump’ in Rn_ provided by the turbulence stimulation device is clearly observed in the results. However, further research is required in order to produce a useful tool for test engineers to size and place turbulence stimulation devices on models.

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