Compilation Report on the Effects of Distortion; From the Writing of John J. Franco and James E. Glover.

摘要

In the 1930s, 1940s, and 1950s, the U.S. Army Engineer Waterways Experiment Station (WES) conducted several series of studies to investigate the effects of distortion, differing horizontal and vertical scales, on physical model results. This report presents the portion of those investigation conducted from 1954 to 1961. The results had not been previously published; however, the two WES researchers, the late Messrs. John J. Franco and the late James E. (Ed) Glover, had prepared various unpublished documents of these investigations. Therefore, this report is a compilation of those writings and supporting data, as well as this author s conclusions and applicability of the effects of distortion investigations to physical, movable-bed models using lightweight bed materials. The investigations conducted by Franco and Glover involved two specific series of tests. Those series were: a. Plan A, Series 1. These tests were conducted using distortions of 0, 2, 4, 6, 8, and 10. The horizontal scale used was 1:200 with subsequent vertical scales of 1:200, 1:100,1:50, 1:33.33, 1:25, and 1:20, respectively. The tests were conducted following the Froude criteria to determine the appropriate velocity and discharge scales for these tests. b. Plan A, Series 2. These tests were conducted using distortion ratios of 0, 2, 3, and 4. The horizontal scale used was 1:400. This series of tests was conducted somewhat different than Series 1, with the velocity held constant at the 0-distortion value and the depth varied from the 0-distortion to the 4-distortion value. The depth was then held at the 4- distortion value and the velocity varied from the 0-distortion to the 4- distortion value. Some of these tests were conducted with the Froudian scale relationships not followed to isolate either velocity or depth of flow impacts.