COMPUTER FLUID DYNAMICS DETERMINATION OF INSIDE DOMAIN WAVES BLAST DEVELOPMENT PROCESS

Autor/autori: Lecturer Eng. Ioan Sorin LEOVEANU, PhD

Rezumat: In ultima perioada de timp, datorita cresterii puterii de calcul si a perfectionarii continue a metodelor numerice destinate descrierii proceselor fizice complexe, acestea au fost implementate in aplicatii ingineresti care sa asigure un nivel cat mai ridicat de siguranta in exploatare. In acest sens, lucrarea isi propune analiza modului de propagare a undelor de soc produse de o explozie generata intr-un domeniu inchis, utilizand o metoda de modelare a dinamicii gazului bazata pe rezolvarea ecuatiilor Euler pentru domenii 2D sau 3D cu configuratie oricat de complexa. In prezent, astfel de probleme au fost modelate utilizand metode bazate pe viteza de ardere a combustibilului si propagare a undelor de presiune, bazate pe metoda impulsiva [1, 3]. La baza acestor metode stau determinarile experimentale, facute pentru fiecare tip de exploziv in parte. De regula, in multe cazuri, mai ales in ultimul timp, sunt folosite diverse retete de explozibili, al caror impuls si caracteristici explozive nu sunt cunoscute in prealabil. Din aceasta cauza, in lucrarea de fata s-a cautat o solutie energetica avand un grad mare de generalitate. La baza dezvoltarii algoritmilor din lucrare stau metode de tip TVD, iar interactiunea cu peretii a fost obtinuta prin impunerea conditiilor de frontiera pentru diversele configuratii geometrice din apropierea zonei de frontiera solid-gaz. Astfel, se obtine un model de propagare a undelor de soc in interiorul unui domeniu oricat de complex. In lucrare s-a utilizat un domeniu 3D cu laturi egale, cu descarcarea energetica in centrul acestuia, problemele legate de geometrii foarte diverse, fiind de fapt diverse reasezari ale conditiilor la limita deja dezvoltate in lucrare.

Cuvinte cheie: modelare folosind dinamica fluidului, unda de soc, explozie, sistem de alimentare, structura de alimentare.


Abstract: In the last time period, the computer power increase day by day and the numerical methods dedicated to modeling the more complexes physical phenomenon are more accurate and simples. Those models are in trends to be used in the engineering design of diverse products and get higher safety and efficiency. In that trends, the paper want to analyze the wave’s blast propagation inside the 2D/3D complexes closes domains. This type of problems was analyzed in diverse research works [1,3] based on the specific impulse method, for each knotweed propeller or explosive. As is known, in many cases, in the last age, more of explosives used consist in diverse mixtures with unknown experimental specifically impulse or other characteristics. This is the cause of developing other solution types, based of energetically solution with great generalization applications. The method is based on volume finite method, VOF, with flux limiter between adjacent cells developed in TVD technique. The walls boundary cells, considerate the case solid-gas boundary where for density is used the method of ghost cells and for moments and energy was used the classical RENS methods. In this way a new method of simulation of blast waves inside domains 3D with great complexity is get and tested on an explosion located in the middle of a cubic space, case that put in oeuvre all the boundary cases specifically of 3D modeling and the quickly evaluation of software program developed become more easy and the loading pressures systems dynamics too.

Keywords: computer fluid dynamics, wave’s blast, explosion, loading system, structural loading

 

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