Scale Effects in Scour Physical-Model Tests: Cause and Alleviation

Scale effect occurs when a prototype hydraulic process is simulated at a laboratory scale due to dissatisfaction of similarity laws. It might lead to considerable deviation when the model scour depth is extrapolated to prototype value. Three popular experimental approaches including prediction-equation-targeted flume test, series-model test and similitude-model test are reviewed with emphasis upon their merits and limitations in reducing or alleviating scale effects. Scale laws guiding scour physical-model design are discussed for performing cost-effective model tests. An empirical equation is further derived from data of clear-water pier scour experiments to examine the test results in up-scale extrapolating. It is suggested that scale effect in a scour physical model test could be efficiently reduced if both the mobility similarity of bed particles and Froude number similarity are satisfied simultaneously.

並列關鍵字

scale effect ； similarity law ； scour ； physical model

參考文獻

Emmett, M. L., “Scale Effect in Pier-Scour Experiments,” Journal of Hydraulic Engineering, Vol. 125, No. 8, pp. 894-895 (1999).

Ettema, R., Melville, B.W. and Barkdoll, B., “Scale effect in pier-scour experiments,” Journal of Hydraulic Engineering，Vol. 124, No. 6, pp. 639–642 (1998).

Ettema, R. and Melville, B.W., “Scale effect in pier-scour experiments,” Journal of Hydraulic Engineering, Vol. 125, No. 8, pp. 894-895 (1999).

Ettema, R., Kirkil, G. and Muste, M., “Similitude of large-scale turbulence in experiments on local scour at cylinders,” Journal of Hydraulic Engineering, Vol. 132, No. 1, pp. 33–40 (2006).

Heller, V., Hager, W.H. and Minor, H.-E., “Scale effects in subaerial landslide generated impulse waves,” Experiment in Fluids, Vol. 44, No. 5, pp. 691-703 (2008).

國際替代計量

Scale Effects in Scour Physical-Model Tests: Cause and Alleviation

未授權

主題瀏覽