Accession Number:

ADA604702

Title:

Modeling Navigation Conditions at Lock Approaches

Descriptive Note:

Technical note

Corporate Author:

ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB

Personal Author(s):

Report Date:

2001-12-01

Pagination or Media Count:

13.0

Abstract:

INTRODUCTION The lock approach research required the development of a method to rapidly evaluate the navigation conditions in lock approaches for various guard wall configurations. The idea was to numerically model many guard wall configurations and then evaluate the most promising designs in the physical model. The method was to select a numerical modeling technique and then evaluate the appropriateness of the model s use validate with comparisons to laboratory data. If the model adequately simulated the flow field produced by a guard wall, then various designs would be modeled in an attempt to gain general insight into the controlling features of guard walls. These simulation results could then be used to develop design ideas for further testing in the physical model. MODEL CONSIDERATIONS The choice of modeling method is important. The geometry of the guard wall dictates the flow patterns in the lock approach. Therefore, the numerical flow model had to be designed so that only the geometrical parameters of the wall were changed from design to design and that the model would not rely on empirical coefficients. Empirical rules such as head-discharge relations rely on coefficients that can be dependent on the flow. For example, the discharge coefficient is sensitive to the direction of the flow relative to the control structure. Rather, a model was needed that relied on a physical description of the design to compute the flow passing under the guard wall. The next consideration was the dimensionality of the model. Obviously, a one-dimensional description would not provide the lateral variability of the flow and so would not provide a means of estimating outdraft or draw toward the guard wall.

Subject Categories:

  • Civil Engineering
  • Land and Riverine Navigation and Guidance

Distribution Statement:

APPROVED FOR PUBLIC RELEASE