Yasin Şöhret

Customised application of exergy analysis method to PW120A turboprop engine for performance evaluation

In this paper, first and second laws of thermodynamics are applied on a turboprop engine of a regional aircraft. Performance parameters of the engine are assessed under take-off conditions and maximum power settings. Energy and exergy rates, exergy destruction rate, improvement potential, fuel depletion rate and productivity rate are proven by using component-based analysis method. Exergy destruction rates are found to be 337.12 kW, 1461.87 kW, 69.74 kW and 269.22 kW in order of air compressor, combustion chamber, gas turbine and free turbine. In addition, exergy efficiencies of the air compressor, combustion chamber, gas turbine and free turbine are calculated to be 86.95%, 82.16%, 97.86% and 85.52%, respectively, whilst energy and exergy efficiencies of the engine are found to be with the values of 27.89% and 26.74%. Obtained results from this study can be useful to improve performance of a turboprop engine still in service.

An Environment-Friendly Engine Selection Methodology for Aerial Vehicles

ABSTRACT Emitted exhaust gases from aircraft are an issue of concern from an environmental perspective. Many research studies have been conducted aiming to reduce aircraft emissions in the hope of preventing any further increase in climate change and global warming. Within this scope, the present study intends to present a methodology for an optimum gas turbine engine selection with regard to emitted exhaust gases. The methodology focuses on five different turbofan engines which constitute the power unit of a commonly used passenger aircraft. At the end of the study, it is considered to be impossible to achieve a minimum exhaust emission for each gas. For this reason, it is considered to be better to optimize the engine with the aim of reducing nitrogen oxide emissions or other exhaust emissions.

Mathematical Modelling for Carbon Dioxide Equivalent Prediction of Greenhouse Gases Emitted from a Small Scale Turbojet Engine

In this paper, a small scale engine is investigated in terms of emissions characteristics. Within this context, emitted greenhouse gases are measured in accordance of relevant regulations. Obtained emissions data is evaluated with the aid of a novel mathematical model. Presented mathematical model is developed to predict carbon dioxide equivalent of greenhouse gases emitted from a small scale turbojet engine. At first, emissions data of the engine is used to find emission index based upon combustion equilibrium. Afterwards, a novel correlation among emission index and carbon dioxide equivalent is put forth. Developed mathematical model can be beneficial to those who deal with emissions characteristics and environmental assessment of aircraft engines, especially turbojet engines. 1 Doctorate Student, Graduate School of Sciences, Anadolu University Yunusemre Campus, Student Member of AIAA. 2 Prof. Dr., Faculty of Aeronautics and Astronautics, Anadolu University Iki Eylul Campus. 3 Dr., Department of Chemistry, Eskisehir Osmangazi University Meselik Campus. Kucuk Bir Turbojet Motordan Salinan Sera Gazlarinin Karbon Dioksit Esdegerliginin Tahminlenmesi Icin Matematiksel Model Yasin Şohret, Tahir Hikmet Karakoc Anadolu University, Eskisehir, 26470, Turkey Nimet Karakoc Eskisehir Osmangazi University, Eskisehir, 26030, Turkey

Greenization Factor of a Turbojet Engine

The environmental issues associated with energy consumption and increasing energy demand are a major concern of this century. To reduce environmental impact and achieve more sustainable society, novel approaches are developed day by day. In the current chapter, a novel approach to evaluate environmental impact of a turbojet engine is presented. Recently defined, a genuine indicator, namely, greenization factor, is a measure to understand contribution of the system improvement to environmental impact reduction. The current study aims to derive this indicator defined for other energy conversion systems to assess propulsion systems from the same perspective. For this purpose, an application to a turbojet engine is also introduced for a better understanding of the methodology.

Statistical Model Development for Military Aircraft Engine Exhaust Emissions Data

Statistical regression models have a wide usage in various estimation problems. They can be used to find a relationship between dependent and independent variables. Generally, it is using regression parametric models to find the type of relationship between variables. But some problems could not be estimated with linear models, as they have a nonlinear effect on dependent variable. This study aims to show the difference between linear and nonlinear techniques. In this study, emission parameters of a military-type turboprop engine is determined at unmeasured operating points on the basis of data collected at various loads with the aid of regression techniques. It is using multivariate linear regression, additive models with B-spline basis function, and smoothing splines. Three different techniques used to reveal best approximation to the dataset. It is observed that the effect of three parameters: revolution per minute (min-1), air/fuel ratio (kg air/kg fuel), and mass flow rate (kg.s-1) to different mass flow rates (CO (kg/s), CO2 (kg/s); UHC (kg/s), NO2 (kg/s)). In the end of the study, results obtained from benefited approximations were compared with each other using MSE (mean squared error) performance criteria.

Exergy indicators of a low-emission aero-engine combustor

Purpose It is essential to develop more environment-friendly energy systems to prevent climate change and minimize environmental impact. Within this scope, many studies are performed on performance and environmental assessments of many types of energy systems. This paper, different from previous studies, aims to prove exergy performance of a low-emission combustor of an aero-engine. Design/methodology/approach It is a well-known fact that, with respect to previous exergy analysis, highest exergy destruction occurs in the combustor component of the engine. For this reason, it is required to evaluate a low-emission aero-engine combustor thermodynamically to understand the state of the art according to the authors’ best of knowledge. In this framework, combustor has been operated at numerous conditions (variable engine load) and evaluated. Findings As a conclusion of the study, the impact of emission reduction on performance improvement of the aero-engine combustors exergetically is presented. It is stated that exergy efficiency of the low-emission aero-engine combustor is found to be 64.69, 61.95 and 71.97 per cent under various operating conditions. Practical implications Results obtained in this paper may be beneficial for researchers who are interested in combustion and propulsion technology and thermal sciences. Originality/value Different from former studies, the impact of operating conditions on performance of a combustor is examined from the viewpoint of thermodynamics.

Sustainability Assessment of a Turboprop Engine: Exergy-Based Method

Sustainable energy utilization is a necessary to reduce environmental impact and combat global warming in twenty-first century. For this purpose, sustainability parameters of a turboprop engine are presented with exergetic approach in this study. At first, commonly used sustainability assessment methods are summarized. Then, fundamentals of exergy analysis and sustainability terms are explained in details. After all, a turboprop engine is evaluated from this viewpoint to exemplify the explained methodology. As a result of the component based exergy analysis, exergy efficiency of the air compressor, combustion chamber, gas turbine and power turbine are found to be 87.04 %, 74.50 %, 89.0 % and 92.23 %, respectively, whereas exergy efficiency of the overall engine is 38.09 %. In the sustainable framework; waste exergy ratio, recoverable exergy rate, exergy destruction factor, environmental effect factor and exergetic sustainability index of the overall engine are found to be in order of 0.43, 0.00, 0.20, 4.38 and 0.23.

Exergy Approach to Evaluate Performance of a Mini Class Turboprop Engine

In this chapter, performance assessment of a mini class turboprop engine is presented. Exergy analysis is used for this purpose on the basis of applicability on thermal systems. As a result of the component-based exergy analysis, relative irreversibility of the combustion chamber is higher relatively. Exergy destruction rates within the air compressor, combustion chamber and gas turbine components are 24.08 kW, 100.76 kW and 15.80 kW respectively. Additionally, exergy efficiencies of the components are 74.11, 69.68 and 98.99 % in order of air compressor, combustion chamber and gas turbine.

ANFIS-based comparative exhaust gases emissions prediction model of a military aircraft engine

In this paper, comparison of estimation methods for exhaust gaseous emissions developed for a military aircraft engine via adaptive neuro-fuzzy inference system (ANFIS) structure is introduced. For system identification process, combustion efficiency, engine shaft RPM and air-fuel ratio are preferred to be system inputs to obtain emission indexes of carbon monoxide, carbon dioxide, nitrogen oxides and unburned hydrocarbon as system outputs. While comparing the estimation methodologies, two clustering methods in adaptive neuro-fuzzy inference system structure, grid partitioning and subtractive clustering, are benefited to define membership functions. Hybrid optimisation is preferred in training parts. As a conclusion remark of the present study, estimation error values of both clustering methods are found for different number of membership functions with the common training method. Nonetheless, training time saving is the advantage of subtractive clustering method in our study.

GAZ TÜRBİNLİ MOTORLARIN YANMA VERİMİNİN EMİSYON VERİLERİ KULLANILARAK MATRİS YÖNTEMİ İLE ÇÖZÜMÜ VE UYGULAMASI

Gaz turbinli motorlar, tasarim asamasi tamamlandiktan sonra yanma odasi, montaj oncesi ve montaj sonrasi testlere tabi tutulur. Yanma odasinin farkli noktalarindan olculen basinc, sicaklik, debi ve cikis noktasindan olculen emisyon degerleri, tasarim parametreleri ve farkli yazilimlar kullanilarak elde edilen kati model analiz sonuclariyla kiyaslanarak tasarim dogrulama calismalari gerceklestirilir. Bu anlamda olculmus olan emisyon verileri, yanma verimliliginin belirlenmesi icin onem tasimaktadir. Bu calisma kapsaminda, olculen emisyon degerleri kullanilarak yanma veriminin hesabina iliskin bir matris cozum yontemi gelistirilmistir. Gelistirilen bu matris cozum yontemi kullanilarak, bir turbofan tipi ucak motorunun yanma verimi hesabi gerceklestirilmis ve yanma verim degeri %99,93 olarak bulunmustur