Search results for "Anàlisi numèrica"
showing 5 items of 5 documents
High order finite difference schemes for hyperbolic conservation laws on complex domains: extrapolation and time integration techniques
2016
Els esquemes d’alta resolució de tipus shock capturing s’empren àmpliament en el càlcul d’aproximacions numèriques precises de la solució de molts sistemes de lleis de conservació hiperbòliques, especialment en dinàmica computacional de fluids. En aquest context, l’aplicació de condicions de frontera adequades en dominis amb geometria complexa s’ha convertit en un problema amb una certa dificultat que s’ha abordat de diferents maneres segons la naturalesa dels mètodes numèrics i del tipus de malla. En aquest treball presentem una tècnica d’extrapolació d’informació a partir de l’interior del domini computacional a cel·les fantasma destinada a malles cartesianes estructurades (les quals, a d…
Shock control bump design optimization on natural laminar aerofoil
2011
The chapter investigates Shock Control Bumps (SCB) on a Natural Laminar Flow (NLF) aerofoil; RAE 5243 for Active Flow Control (AFC). A SCB approach is used to decelerate supersonic flow on the suction/pressure sides of transonic aerofoil that leads delaying shock occurrence or weakening of shock strength. Such an AFC technique reduces significantly the total drag at transonic speeds. This chapter considers the SCB shape design optimisation at two boundary layer transition positions (0 and 45%) using an Euler software coupled with viscous boundary layer effects and robust Evolutionary Algorithms (EAs). The optimisation method is based on a canonical Evolution Strategy (ES) algorithm and inco…
A Tool for Predicting the Dynamic Response of Biotrickling Filters for VOC Removal
2016
This article presents the development of a MATLAB® computer program to simulate the performance of biotrickling filters. Since these filters behave differently during spraying and nonspraying cycles, the presented simulation tool is built on top of a mathematical description of each situation. The resulting variable-structure model is then used as the basis for simulation experiments. The model presented herein represents the first attempt to take into account the variable spraying pattern usually found in industrial installations. Overall, the software is flexible and easy to use, allowing the user to specify the emission concentration pattern, the gas concentration pattern, as well as the…
Simulazione numerica tridimensionale del campi de moto indotti dal vento
2006
Nell’articolo viene proposto un modello numerico tridimensionale al volume finiti, che viene utilizzato per la simulazione di campi di moto indotti dal mento in corpi idrici con batimetria complessa. I risultati numerici sono confrontati con misure sperimentali. Al fine di verificare gli effetti sul calcolo del campi idrodinamici di alcume ipotesi simplificative, relative alla distribuzione verticale della pressione e degli sforzi di Reynolds, sono stati quindi condotti alcuni test numerici, dai quali si è evidenziato che l’ipotesi di distribuzione idrostatica delle pressioni, cui si fa ricorso nelle approssinazioni di tipo “quasi-3D”, può essere utilizzata per il carcolo del profili vertic…
Static output-feedback control under information structure constraints
2013
An important challenge in the static output-feedback control context is to provide an isolated gain matrix possessing a zero-nonzero structure, mainly in problems presenting information structure constraints. Although some previous works have contributed some relevant results to this issue, a fully satisfactory solution has not yet been achieved up to now. In this note, by using a Linear Matrix Inequality approach and based on previous results given in the literature, we present an e cient methodology which permits to obtain an isolated static output-feedback gain matrix having, simultaneously, a zero-nonzero structure imposed a priori. Peer Reviewed