CFD Application in Thermal Engineering

**Chapter 11**

**Abstract**

and experimental results.

**1. Introduction**

biogas or both.

**Figure 2** [3].

**215**

quasi-constant pressure.

alternative fuels, experiments

CFD Application for Gas Turbine

The current chapter presents the use of computational fluid dynamics (CFD) for simulating the combustion process taking place in gas turbines. The chapter is based on examples and results from a series of applications developed as part of the research performed by the authors in national and European projects. There are envisaged topics like flame stability, pollutant emission prediction, and alternative fuels in the context of aviation and industrial gas turbines, growing demands for lower fuel consumption, lower emissions, and overall sustainability of such energetic machines. Details on the available numerical models and computational tools are given along with the expectation for further developing CFD techniques in the field. The chapter includes also some comparison between theoretical, numerical,

Gas turbines are energetic machines based on Brayton thermodynamic cycle [1]

In **Figure 1**, evolution (1–2) represents the real compression evolution of the working fluid into the compressor, (2–3) represents combustion at constant pressure, (3–4) represents real expansion of the working fluid into the turbine, and (4–1) represents the cooling down of the working fluid at constant pressure, usually the atmospheric one. Evolutions (1–2is) and (3–4is) are the isentropic compression and isentropic expansion, respectively, and they are shown on the graphic in order

Unlike compressors and turbines in which only pure gas-dynamic processes develop, combustion involves also chemical reactions between air and fuel, resulting in flue gases driving the turbine. Since combustion is known from ages, the overall efficiency of it is very high [2] and enhanced by the high pressure provided by the compressor. Still, many current studies are directed on this subject willing to reduce pollutant emissions or to accommodate alternative fuels such as

In general, the combustion process is organized into the gas turbine as shown in

Combustion Simulations

*Valeriu Vilag, Jeni Vilag, Razvan Carlanescu,*

**Keywords:** combustion, gas turbine, numerical simulations, models,

(**Figure 1**) meaning, among others, temperature rise using combustion at

to emphasize the difference between real and ideal (isentropic).

*Andreea Mangra and Florin Florean*
