Sylvain Detrembleur

Depth-integrated flow modelling taking into account bottom curvature

Successfully modelling flows over a spillway and on strongly vertically curved bottoms is a challenge for any depth-integrated model. This type of computation requires the use of axes properly inclined along the mean flow direction in the vertical plane and a modelling of curvature effects. The proposed generalized model performs such computations by means of suitable curvilinear coordinates in the vertical plane, leading to a fully integrated approach. This means that the flows in the upstream reservoir, on the spillway, in the stilling basin and in the downstream river reach are all handled in a single simulation. The velocity profile is generalized in comparison with the uniform one usually assumed in the classical shallow water equations. The pressure distribution is modified as a function of the bottom curvature and is thus not purely hydrostatic. Representative test cases, as well as the application of the extended model to the design of a large hydraulic structure in Belgium, lead to satisfactory validation results

Detailed inundation modelling using high resolution DEMs

Abstract With the availability of high resolution DEMs, relevant and detailed inundation maps may now be routinely computed provided that suitable flow models are available. The full 2D flow model presented in this paper has been used to compute such maps on 800 km of the main rivers of the Walloon Region in Belgium. The use of grid spacing of 1 m, similar to the DEM resolution, enables the accurate prediction of the pattern of flood depth. This is confirmed by several application examples, which also demonstrate the ability of the model to reproduce depth measurements for a wide range of flood discharges without the need for recalibration of the roughness coefficient. The numerical model has been systematically validated by comparison with observations during recent real flood events. It shows a very good agreement with field data, in particular the free surface elevations and inundation extension.

Integrated Flood Risk Analysis for Assessing Flood Protection Strategies

The present chapter describes an end-to-end methodology for assessing flood protection strategies, including the whole methodological process from hydrological statistics to detailed 2D hydraulic modelling, damage calculation and flood risk evaluation. This risk-based approach serves as a component of a decision-support system (DSS) developed in Belgium for identifying cost-effective flood management strategies in the context of climate change. The DSS accounts for both hydraulic and socio-economic parameters to quantify the benefits (in terms of avoided risk) and the cost of each strategy. Besides reviewing fundamentals of flood risk assessment, including the inundation model and main concepts related to flood risk, a consistent methodology for micro-scale flood risk analysis is presented in detail, combining complementary sources of GIS information such as high resolution and high accuracy land use database as well as socio-economic datasets. Finally a case study on a main tributary of river Meuse in Belgium is described. DOI: 10.4018/978-1-61520-907-1.ch012

On the advantage of using risk curves to assess flood protection measures

Modern flood management approaches require the quantification of flood risk, accounting for the hazard component (flood frequency and inundation intensity) as well as the vulnerability of the floodplains (exposure, value and susceptibility). In this chapter, we present a detailed flood risk model, in which flow computation, monetary valuation of the assets and damage calculation are conducted at the scale of individual buildings or facilities. To avoid the shortcoming of focusing on economic damage, psycho-social impacts of floods are also included in the analysis. The model has been applied to evaluate three flood protection measures on a river reach in the Meuse basin (Belgium). The resulting risk curves show that such a micro-scale risk analysis provides important insights into the relative influence of the different flood protection measures. This could neither be evaluated through a more standard hydraulic analysis nor through the quantification of flood risk by only a single number.

Modeling the Vertical Spincasting of Large Bimetallic Rolling Mill Rolls

In order to take into account the dynamic effects of molten metal during solidification, a methodology is presented to interface a metal solidification solver (coupled thermal mechanical metallurgical finite elements solver) with a specifically developed flow dynamics solver. (flow dynamics and thermics finite volume solver) The numerical set of tools is designed to be used for the simulation of bimetallic hot rolling mill rolls vertical spincasting. Modeling the industrial process for these products imply certain specifications on the numerical methods used, mainly due to the size of the geometrical domain, low Rossby & Ekman numbers, and a high Reynolds number.

Hydrodynamic forces acting on vertically translating bodies in free surface water

The dynamics of free surface flow induced by a partially or totally submerged moving body generates non-straightforward effort distribution. In the design process of moving hydraulic structures and their operation device, the pressure field acting on them is of prime interest. A fundamental example of such a phenomenon, namely the vertical uplift of a submerged horizontal rigid sheet, is hereafter experimentally analyzed. The present study includes the description of the experimental apparatus built in the HACH laboratory and the description of the rigorous experimental procedure used. The purpose of the analysis is to identify the fundamental hydrodynamic mechanisms involved.