MACH SAYISININ TURBOJET MOTORU TERMODİNAMİK VERİMLERİ ÜZERİNDEKİ ETKİSİ: BİR UAV UYGULAMASI

Year 2018, Volume: 7 Issue: 2, 848 - 863, 20.07.2018

Önder Turan

https://doi.org/10.28948/ngumuh.445287

Abstract

Hava araçlarının karmaşık yapılı sistemler olup
tasarım süreçleri detaylı analizlere ihtiyaç duyarlar. Sonraki nesil uçaklarda
itki sistemlerinin performansı için termodinamiği kurallarını kullanmak
gereklidir. Bu sebeple termodinamiğin I. ve II. Kanunlarını, akışa ve momentum
dengesine uygulamak gereklidir. Bu çalışmada, küçük bir turbojet motorunun
enerji ve ekserji performansı üzerinde uçuş Mach sayısının etkileri, uçuş
irtifası  8,000 m alınarak incelenmiştir.  0.3≤ M₀≤0.8 aralığında motorun
ekserji verimi %48.61-49.88, enerji verimi 
%3.25-9.96, olarak hesaplanmıştır. 
Bu ana verimlere ilave olarak,  
kompresör  ekserji verimi %89.45,  yanma odası ekserji verimi %61.11, türbin
ekserji verimi %89.21 ve egzoz ekserji verimi 84.15 olarak hesap edilmiş olup,
uçuş Mach sayının arttıkça ekserji yıkımının da düşük miktarda azaldığı
görülmüştür.

Keywords

Turbojet, ekserji, enerji, UAV, IHA

MACH NUMBER EFFECT ON THE THERMODYNAMIC EFFICIENCIES OF A TURBOJET ENGINE: AN UAV APPLICATION

Abstract

Air vehicles have evolved into extremely complex
systems that need detail analysis and tools for an efficient design process. A
theoretical formulation based on law of thermodynamics is proposed for
assessing the propulsive performance of future aircraft configurations. It
consists of the combination of a momentum balance and a fluid flow analysis
involving the first and second laws of thermodynamics. To meet this need, this
study presents and evaluates flight Mach number (M₀) effects on
energetic and exergetic performance of a small turbojet engine. Energy and
exergy analysis are applied to a small turbojet engine to examine the effects
of using different aircraft velocities at constant reference environment
(flying altitude is assumed to be constant at 8,000 m). The results of analysis
using 0.3≤ M₀≤0.8 are the exergetic and energetic efficiency ranging
from 48.61% to 49.88% and 3.25% to 9.96%, respectively. Furthermore, exergy
efficiency values were found to be 89.45% for the centrifugal compressor, 61.11
% for the combustion chamber and 89.21% for the turbine, and 84.15% for the
exhaust, while engine exergy destruction is also slight decrease with flight
Mach number.

Keywords

Turbojet, exergy, energy, UAV, IHA

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