Flow Pressure Behavior Downstream of Ski Jumps

Agostino Lauria,Giancarlo Alfonsi,Ali Tafarojnoruz

doi:10.3390/fluids5040168

Abstract

Ski jump spillways are frequently implemented to dissipate energy from high-speed flows. The general feature of this structure is to transform the spillway flow into a free jet up to a location where the impact of the jet creates a plunge pool, representing an area for potential erosion phenomena. In the present investigation, several tests with different ski jump bucket angles are executed numerically by means of the OpenFOAM® digital library, taking advantage of the Reynolds-averaged Navier–Stokes equations (RANS) approach. The results are compared to those obtained experimentally by other authors as related to the jet length and shape, obtaining physical insights into the jet characteristics. Particular attention is given to the maximum pressure head at the tailwater. Simple equations are proposed to predict the maximum dynamic pressure head acting on the tailwater, as dependent upon the Froude number, and the maximum pressure head on the bucket. Results of this study provide useful suggestions for the design of ski jump spillways in dam construction.

Highlights

In the field of dam construction, ski jump spillways have been studied for several decades, through the application of simple techniques in earlier investigations
10) may be considered a useful tool to estimate the maximum dynamic pressure heads acting on tailwaters and buckets of the ski jump spillways
The issue of the dynamic pressure head acting on the tailwater and the bucket of a ski jump jet has been investigated in detail

Summary

Introduction

In the field of dam construction, ski jump spillways have been studied for several decades, through the application of simple techniques in earlier investigations. [1,2,3], one can obtain a summary of recommended characteristic parameters for the realization of ski jumps (see [4] for a critical review of formulas for the prediction of scour depth beneath jets from flip buckets). In this field, some experimental studies have been published. Experimental results were analyzed to study the hydraulic properties of energy dissipation in terms of flow discharge, jet characteristics, and hydrodynamic pressure. Afterwards, several simulations are executed, with particular attention paid to the maximum value and distribution of pressure heads at critical zones where the jet impacts

Materials and Methods

Results and Discussion

Visual

Correlations between approach

Conclusions