Poboljšani aerodinamički proračun transoničnog otpora aeroprofila pri zonalnom modeliranju strujnog polja

Abstract

Pri projektovanju savremenih komercijalnih vazduhoplova visoka ekonomičnost leta jedan je od najbitnijih zahteva koje treba ispuniti. Pored izbora ekonomičnih motora, vrlo bitna stavka za zadovoljenje ovog uslova je i primena savremenih tehnika pri aerodinamičkom projektovanju. Veliki broj ovih vazduhoplova krstari brzinama koje su nešto manje od brzine zvuka, pa je uzgonske površine i njihove aeroprofile potrebno optimizirati prevashodno za ovaj domen. Jedan od prvih koraka u tom procesu je izbor ili namensko projektovanje aeroprofila za krilo i ostale uzgonske površine konkretne letelice koji će proizvoditi što manji talasni otpor u krstarećem letu. Numerička optimizacija aeroprofila danas predstavlja izuzetno važan deo tog postupka. Algoritam prikazan u ovom radu omogućava numerički proračun talasnog otpora kako na postojećim tako i na aeroprofilima koji se namenski prave za određenu letelicu i prevashodno je namenjen operativnom aerodinamičkom projektovanju vazduhoplova. Algoritam je relativno jednostavan i vrlo pouzdan, što je pokazano poređenjem rezultata koje on daje u okviru programa nazvanog Tranpro sa eksperimentalnim rezultatima iz nekoliko najkompetentnijih svetskih vazduhoplovnih centara koji se bave ovom problematikom .

Very high cost efficiency of the flight is a crucial requirement specially in the contemporary commercial airplane design. Beside the low engine fuel consumption, advanced aerodynamics is another dominant factor which must be satisfied to fulfill this request. Many of these aircraft cruise at speeds slightly lower than the speed of sound, so their lifting surfaces and corresponding airfoils must be optimized primarily for this domain. One of the first steps in that process is selection or even design of the customized airfoils for the particular wing and other lifting surfaces that will produce the least possible shock wave drag in cruising flight. Nowadays the numerical airfoil optimization is very important part in that process. Algorithm presented in this paper enables the numerical calculation of wave drag both for the existing and the airfoils designed specially for a certain aircraft, and it is primarily aimed for use in the operational aircraft design. This algorithm is fairly simple and very reliable, which has been proven by comparing it’s results, obtained through the computer program Tranpro, with the experimental results for airfoils tested at several most competent aeronautical institutions throughout the world .