scholarly journals Design and development of combustion chambers for gas turbine engines based on calculations of various levels of complexity

2021 ◽  
Vol 20 (3) ◽  
pp. 7-23
Author(s):  
Y. B. Aleksandrov ◽  
T. D. Nguyen ◽  
B. G. Mingazov

The article proposes a method for designing combustion chambers for gas turbine engines based on a combination of the use of calculations in a one-dimensional and three-dimensional formulation of the problem. This technique allows you to quickly design at the initial stage of creating and development of the existing combustion chambers using simplified calculation algorithms. At the final stage, detailed calculations are carried out using three-dimensional numerical calculations. The method includes hydraulic calculations, on the basis of which the distribution of the air flow passing through the main elements of the combustion chamber is determined. Then, the mixing of the gas flow downstream of the flame tube head and the air passing through the holes in the flame tube is determined. The mixing quality determines the distribution of local mixture compositions along the length of the flame tube. The calculation of the combustion process is carried out with the determination of the combustion efficiency, temperature, concentrations of harmful substances and other parameters. The proposed method is tested drawing on the example of a combustion chamber of the cannular type. The results of numerical calculations, experimental data and values obtained using the proposed method for various operating modes of the engine are compared.

2018 ◽  
Vol 209 ◽  
pp. 00019
Author(s):  
Michael Yurievich Orlov ◽  
Oleg Vladimirovich Kolomzarov ◽  
Vladislav Mikhailovich Anisimov ◽  
Nikita Igorevich Gurakov ◽  
Nikolai Sergeevich Mironov

The interrelations between the size of the gas turbine engine (GTE) and the size and workflow of the combustion chamber (CC) were considered. On the base of analysis of workflow organization the design of CC with toroidal recirculation mixing zone was proposed. The theoretical justification of chosen design was carried out on the base of comparison of combustion volumes, which formed in traditional CC with swirlers and in proposed CC. The comparison of combustion volumes, schematic display of combustion zones with a discrete flame and a combined combustion zone were given.


Author(s):  
John T. Lindsay ◽  
C. W. Kauffman

Real Time Neutron Radiography (RTNR) is rapidly becoming a valuable tool for nondestructive testing and basic research with a wide variety of applications in the field of engine technology. The Phoenix Memorial Laboratory (PML) at the University of Michigan has developed a RTNR facility and has been using this facility to study several phenomena that have direct application to internal combustion and gas turbine engines. These phenomena include; 1) the study of coking and debris deposition in several gas turbine nozzles (including the JT8D), 2) the study of lubrication problems in operating standard internal combustion engines and in operating automatic transmissions (1, 2, 3), 3) the location of lubrication blockage and subsequent imaging of the improvement obtained from design changes, 4) the imaging of sprays inside metallic structures in both a two-dimensional, standard radiographic manner (4, 5) and in a computer reconstructed, three-dimensional, tomographic manner (2, 3), and 5) the imaging of the fuel spray from an injector in a single cylinder diesel engine while the engine is operating. This paper will show via slides and real time video, the above applications of RTNR as well as other applications not directly related to gas turbine engines.


Author(s):  
Somnath De ◽  
Prasanna Mondal ◽  
Gourav Manohar Sardar ◽  
Rakin Bin Bokhtiar ◽  
Arijit Bhattacharya ◽  
...  

Abstract The main problem for using reliable and stable diffusion combustion in modern gas turbine engines is the production of NOx at a higher level which is not permissible for maintaining the healthy environment. Thus, combustion in lean premixed mode has become the most promising technology in many applications related to power generation gas turbine, industrial burner etc. Although the lean combustion minimizes NOx production, it suffers from an increased risk of lean blowout (LBO) when the requirement of thrust or load is low. It mainly occurs at the lean condition when the equilibrium between the flame speed and the unburnt air-fuel mixture velocity is broken. Current aircraft gas turbine engines operate fuel close to the combustion chamber which leads to the partially premixed combustion. Partially premixed combustion is also susceptible to lean blowout. Therefore, we have designed a swirl-stabilized dump combustor, where different lengths of fuel-air mixing are available. Our present work aims at improving the combustion stability by incorporating a secondary fuel injection through a pilot arrangement connected with the combustion chamber for premixed as well as partially premixed flames. Incorporation of the pilot system adds a small fraction of the total fuel into the combustion chamber directly. This investigation shows significant extension of the LBO limit towards leaner fuel-air mixture while the NOx emission in the combustion chamber is within the permissible limit. This result can be used for aircraft operators during the process of landing when fuel supply has to be decreased to reduce engine thrust or for power plants operating at low loads. The study of control is based on the colour variation of the flame which actually defines the changes in combustion characteristics. For early detection of LBO, the ratio between the intensity of red and blue colour obtained from flame images with a high speed camera is used. As LBO is approached, the ratio of red to blue intensity falls monotonically. When the ratio falls below a preset threshold, a small fraction of the total fuel is added to the central pilot line. This strategy allows the LBO limit to be shifted to a much lower equivalence ratio (maximum 20% and 11% for fully premixed and least premixed flames, respectively) without any significant increase in NOx production. The analysis includes a feedback control algorithm which is computed in MATLAB and the code is embedded in Labview for hardware implementation.


2020 ◽  
Vol 2020 (4) ◽  
pp. 65-71
Author(s):  
Yu.A. Kvasha ◽  

This work is devoted to the development of approaches to the numerical simulation of 3D turbulent gas flows in different ducts of aircraft gas turbine engines, in particular in inlet device ducts. Inlet devices must provide large values of the total pressure recovery factor and flow uniformity at the engine compressor inlet. The aim of this work is the verification of the operability of a technique developed earlier for the calculation of the parameters of a 3D turbulent flow in complex-shape ducts. The basic approach is a numerical simulation of 3D turbulent gas flows on the basis of the complete averaged Navier¬–Stokes equations and a two-parameter turbulence model. The proposed technique of numerical simulation of a 3D gas flow was tested by calculating a 3D laminar flow in a square pipe bent at a right angle. The calculated flow pattern is in satisfactory agreement with the experimental data on the flow structure in a pipe elbow reported in the literature. Based on a numerical simulation of a 3D turbulent flow in the air duct of one of the air intake configurations for an aircraft turboprop engine, the efficiency of that configuration is assessed. The calculated flow parameter nonuniformity at the air intake outlet, i. e., at the compressor inlet, is compared with that obtained earlier for another air intake configuration for the same engine. It is pointed out that the air intake configuration considered earlier provides a much more uniform flow parameter distribution at the engine compressor inlet. On the whole, this work shows that the quality of subsonic air intakes for aircraft gas turbine engines can be assessed using the proposed numerical technique of 3D gas flow simulation. The results obtained may be used in the aerodynamic improvement of inlet devices for aircraft engines of different types.


Measurement ◽  
2019 ◽  
Vol 139 ◽  
pp. 355-360 ◽  
Author(s):  
M.V. Mekhrengin ◽  
I.K. Meshkovskii ◽  
V.A. Tashkinov ◽  
V.I. Guryev ◽  
A.V. Sukhinets ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document