Univerzitet u Beogradu - Mašinski fakultet, Beograd
Abstract
Ukoliko iz bilo kog tehničkog razloga vazdušne kočnice prestanu da funkcionišu tokom leta, najkritičnija faza u proceduri sletanja jedrilice je finalni prilaz. Pored leta sa bočnim klizanjem, kada se disipacija energije vrši kroz povećanje bočne sile otpora, drugo moguće rešenje ovog problema je ponuđeno u literaturi, gde je pokazano da se dužina prilaza može minimizirati primenom složenih oscilatornih putanja leta. Međutim, let po takvim putanjama zahteva izuzetno letačko umeće. Nasuprot tome, u ovom radu izvršena je analiza jednostavnijih prilaznih putanja, baziranih na harmonijskim promenama brzine, koje je mnogo lakše operativno reprodukovati u letu. U radu je prikazan proračunski algoritam koji omogućava brzu konvergenciju rešenja i analizirana su numerička rešenja za nekoliko tipičnih slučajeva. Kao primer korišćeni su podaci za jedrilicu Vuk-T. Dobijeni rezultati pokazuju nešto manja skraćenja putanja, ali jednostavnost primene u praksi i veća bezbednost predloženih tehnika letenja čini ih korisnim rešenjima u slučaju pomenutih problema.When for any technical reason spoilers become inoperable in flight, the most critical phase of a sailplane landing procedure is final approach. Besides the sideslipping flight possibility, where energy is dissipated through the increased sideforce drag, another solution for this problem has been offered in literature, showing that the landing distance could be minimized using rather complex oscillating flight paths. The problem is that performing such paths in practice would require exceptional piloting skills. Instead of that, in this paper much simpler approach profiles have been analyzed, based on the simple harmonic speed variations, which could much easier be reproduced in practice. After establishing a quick convergence algorithm, numerical solutions for several typical cases, taking the Vuk-T sailplane as an example, have been presented. Although distance reductions are generally smaller than obtained by distance-minimizing techniques, their operational simplicity and higher safety prove them as valuable solutions for this kind of problems
