Effects of residual gas fraction and stroke ratio on the performance and entropy generation of an irreversible Otto cycle

Abstract

Finite-time thermodynamics is often used in realistic analysis of the performance of heat engines. In this study, the effects of residual gas fraction and stroke ratio on engine performance and entropy generation were investigated by taking into consideration the losses such as heat transfer and friction for irreversible Otto cycle. As a result, with the increase of the residual gas fraction, the initial cycle temperature and brake specific fuel consumption increase while the maximum cycle temperature, effective power, thermal efficiency and entropy generation decrease, with the increase of the stroke ratio, the brake specific fuel consumption and entropy generatin increases.

Keywords

• Otto cycle,Entropy generation,Residual gas fraction,Stroke ratio

Artık gaz kesri ve kurs oranının tersinmez Otto çevriminin performansına ve entropi üretimine etkileri

Abstract

Sonlu zaman termodinamiği, ısı motorlarının performansının gerçekçi olarak analizinde sıklıkla kullanılmaktadır. Bu çalışmada tersinmez Otto çevrimi için ısı transferi, sürtünme gibi kayıplar da dikkate alınarak artık gaz kesri ve kurs oranın motor performansına ve entropi üretimine etkileri incelenmiştir. Sonuç olarak artık gaz kesrinin artmasıyla birlikte çevrim başlangıç sıcaklığı ve fren özgül yakıt tüketimi artarken, maksimum çevrim sıcaklığı, efektif güç, ısıl verim ve entropi üretiminin azaldığı, kurs oranının artmasıyla birlikte ise fren özgül yakıt tüketimi ve entropi üretiminin arttığı, efektif güç ve ısıl verimin azaldığı görülmüştür.

Keywords

• Otto çevrimi,Entropi üretimi,Artık gaz kesri,Kurs oranı

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