Influence of Fuel Jet Momentum on Characteristics of a Reverse-Cross Flow Combustor

2017 ◽  
Author(s):  
Shreshtha Kumar Gupta ◽  
Vaibhav Arghode
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Cross Flow ◽  
Pollutant Emissions ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Air Jet ◽  
Fuel Jet ◽  
Thermal Intensity

The current work is aimed towards development of high thermal intensity, low emission combustor for gas turbine engines. Employing discrete and direct injection of air and fuel in a combustion chamber and has been demonstrated to result in low pollutant emissions (NOx, CO, UHC). From our previous investigations, we found that the reverse-cross flow configuration, where air is injected from the exit end and fuel is injected in the cross flow of the injected air, results in favorable combustion and emission characteristics. Though the air jet is the dominant jet, the fuel jet can also influence the flow field, mixing and the combustion behavior inside the combustor, which is the subject of the current investigation. Here we investigate a high thermal intensity combustor relevant to gas turbine engines (at equivalence ratio of 0.8, the combustor operates at thermal intensity of 39 MW/m3-atm and heat load of 6.25 kW). Natural gas is used as the fuel and two different fuel injection diameters of 1 mm and 2 mm are investigated. This result in significantly higher (four times) fuel jet momentum from the smaller fuel injection port as compared to the larger port. From computational fluid dynamics (CFD) studies, it is observed that for the case with higher fuel jet momentum, the fuel jet deflects the air jet such that the flow pattern is significantly altered as compared to the case with lower fuel jet momentum. OH* chemiluminescece images show that the reaction zone location is significantly affected with high momentum fuel jet. NOx is reduced whereas CO is increased with higher momentum fuel jet.

scholarly journals Development of 300 kW Class Ceramic Gas Turbine (CGT302)

1995 ◽  
Author(s):  
Kozi Nishio ◽  
Junzo Fujioka ◽  
Tetsuo Tatsumi ◽  
Isashi Takehara
Keyword(s):  
Gas Turbine ◽  
Development Program ◽  
Pollutant Emissions ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Gas Turbine Engines ◽  
Turbine Inlet Temperature ◽  
Iso Standard ◽  
Current State ◽  
Ceramic Components

With the aim of achieving higher efficiency, lower pollutant emissions, and multi-fuel capability for small to medium-sized gas turbine engines for use in co-generation systems, a ceramic gas turbine (CGT) research and development program is being promoted by the Japanese Ministry of International Trade and Industry (MITI) as a part of its “New Sunshine Project”. Kawasaki Heavy Industries (KHI) is participating in this program and developing a regenerative two-shaft CGT (CGT302). In 1993, KHI conducted the first test run of an engine with full ceramic components. At present, the CGT302 achieves 28.8% thermal efficiency at a turbine inlet temperature (TIT) of 1117°C under ISO standard conditions and an actual TIT of 1250°C has been confirmed at the rated speed of the basic CGT. This paper consists of the current state of development of the CGT302 and how ceramic components are applied.

Advanced Multi-Cup Fuel Injector Technology for Environmentally Responsible Aviation Gas Turbine Engines

2015 ◽  
Author(s):  
Erlendur Steinthorsson ◽  
Adel Mansour ◽  
Brian Hollon ◽  
Michael Teter ◽  
Clarence Chang
Keyword(s):  
Gas Turbine ◽  
Direct Injection ◽  
Pressure Ratio ◽  
Test Facility ◽  
Turbine Engines ◽  
Practical Implementation ◽  
Gas Turbine Engines ◽  
Fuel Injector ◽  
Ambient Conditions ◽  
Environmentally Responsible

Participating in NASA’s Environmentally Responsible Aviation (ERA) Project, Parker Hannifin built and tested multipoint Lean Direct Injection (LDI) fuel injectors designed for NASA’s N+2 55:1 Overall Pressure-Ratio (OPR) gas turbine engine cycles. The injectors are based on Parker’s earlier three-zone injector (3ZI) which was conceived to enable practical implementation of multipoint LDI schemes in conventional aviation gas turbine engines. The new injectors offer significant aerodynamic design flexibility, excellent thermal performance, and scalability to various engine sizes. The injectors built for this project contain 15 injection points and incorporate staging to enable operation at low power conditions. Ignition and flame stability were demonstrated at ambient conditions with ignition air pressure drop as low as 0.3% and fuel-to-air ratio (FAR) as low as 0.011. Lean Blowout (LBO) occurred at FAR as low as 0.005 with air at 460 K and atmospheric pressure. A high pressure combustion testing campaign was conducted in the CE-5 test facility at NASA Glenn Research Center at pressures up to 250 psi and combustor exit temperatures up to 2,033 K (3,200 °F). The tests demonstrated estimated LTO cycle emissions that are about 30% of CAEP/6 for a reference 60,000 lbf thrust, 54.8-OPR engine. This paper presents some details of the injector design along with results from ignition, LBO and emissions testing.

scholarly journals Characteristic Time Correlations of Pollutant Emissions From an Annular Gas Turbine Combustor

1979 ◽  
Author(s):  
A. M. Mellor ◽  
R. M. Washam
Keyword(s):  
Gas Turbine ◽  
Characteristic Time ◽  
Pollutant Emissions ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Gas Turbine Combustor ◽  
Time Model ◽  
Gaseous Pollutant ◽  
Modeling Approach ◽  
Time Correlations

The continuing development of a characteristic time model for gaseous pollutant emissions from conventional gas turbine engines is described. The now engine studied here is the Pratt and Whitney JT9D, and it is shown that universal correlations can be obtained by comparison with previous results. Current limitations of the modeling approach are detailed.

Relight Envelope of a Military Gas Turbine Engine: An Experimental Study

2008 ◽  
Author(s):  
R. K. Mishra ◽  
G. Gouda ◽  
B. S. Vedaprakash
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
Full Scale ◽  
Test Facility ◽  
Turbine Engines ◽  
Engine Fuel ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
Start Up

A twin spool low bypass turbofan engine under development and its combustor in full-scale were tested independently at altitude conditions to establish the relight envelope of the engine. Demonstration of relight capability and defining its boundary are mandatory for military gas turbine engines and for single engine application in particular. The engine was first subjected to windmill to establish its windmilling characteristics. The full engine was then tested for light-off in an altitude test facility simulating windmilling conditions from 4 to 12 km altitude with flight Mach numbers from 0.2 to 1.0. The relight boundary is defined based on the successful light-off points achieved from engine tests. Similar tests were carried out on the full-scale combustion chamber in a stand-alone mode simulating altitude conditions at engine flame-out. The combustor test has defined the light-off and lean blow out limits of the at each point on the relight boundary. The information of fuel-air ratio at light-off and blow-out is very useful in setting the engine fuel schedule for altitude operation and relight. In this paper an attempt is made to highlight various tests carried out on engine and its combustor to define the relight boundary of the engine. The paper also emphasizes the experience of combustor development and associated problems in meeting the relight challenges of military engines. These problems include the necessity of higher fuel-air ratio at high altitudes, the role of additional localized fuel injection through start-up atomizers, and effect of single igniter on relight characteristics. The relight envelope demonstrated by the engine is very satisfactory to meet the first flight requirement where the flight mission generally concentrate in the zone of 0.6 to 0.8 Mach and altitude does not exceed 10 to 12 km. Combustor and atomizer modification is needed to improve relight performance and to shift the boundary to further left.

Analysis of the Fuel Injection in Gas Turbine Premixing Systems by Experimental Correlations and Numerical Simulations

2006 ◽  
Author(s):  
G. Riccio ◽  
L. Schoepflin ◽  
P. Adami ◽  
F. Martelli
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Cross Flow ◽  
Navier Stokes ◽  
Air Stream ◽  
Fuel Jet ◽  
Fuel Mixing ◽  
Gas Turbine Combustion ◽  
The Cross

This paper presents the aerodynamic study of two premixing systems for gas turbine combustion chamber based on detailed CFD 3-D simulations. The work was carried out with the aim to describe the aerodynamic and the mixing process in two different premixing system schemes, typical for DLE gas turbine combustion chamber. Results from different numerical tools (CFD 3-D and 0/1-D) for the estimation of the fuel jet pathway were compared. Both the premixer configurations analysed are related to the cross-flow injection scheme. The first one considers the fuel injection orthogonal to a low swirled air stream while the second one considers the fuel injection directly from hole rows drilled on the suction and pressure side of the swirler blades. The aerodynamic analysis of the premixing devices was focused on the fuel injection in terms of the jets pathway and air/fuel mixing in steady-state conditions. The aerodynamic investigations were performed by CFD 3-D “full Navier-Stokes” codes. Calculations were repeated, on the same mesh, by an in-house developed code (HybFlow) and by commercial codes also. Some previous experimental results were exploited to tune and validate the calculations. Results of the simulation were post-processed in order to allow a quantitative evaluation of the air/fuel mixing. Moreover the calculations were used to verify the accuracy of 0/1-D models, taken from the literature, for the estimation of the maximum penetration and the trajectory for the cross-flow of gaseous fuel jet, considering typical working conditions for gas turbine premixing system. Finally, preliminary considerations related to the fuel injection schemes and to the influence of the main injection conditions on the mixing were carried out.

Numerical Study on the Characteristics of Lean Direct Injection Combustor With Elevated Fuel Temperatures

2020 ◽  
Author(s):  
Jinghe Lu ◽  
Xiao Liu ◽  
Shuying Li ◽  
Enhui Liu ◽  
Zhihao Zhang ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Evaporation Rate ◽  
Numerical Study ◽  
Direct Injection ◽  
Droplet Evaporation ◽  
Turbine Engines ◽  
Mixing Efficiency ◽  
Gas Turbine Engines ◽  
Fuel Temperature ◽  
Lean Direct Injection

Abstract With the development of high performance gas turbine engines, the temperature before turbine is rising and it presents a serious challenge to existing thermal management. It is very attractive to use fuel as the cooling medium for gas turbine engines. For this purpose, the effects of fuel temperature on combustion characteristics are urgently needed to be understood. In this work, the characteristics of lean direct injection (LDI) combustor is simulated by changing the physical properties of fuel with different temperatures. The predictions of gas phase and droplet velocity, droplet diameter are compared well with the experiment data. The numerical results show that as fuel temperature rises, the droplet evaporation rate and mixing efficiency of fuel and air in non-reacting case is improved significantly, the spray angle, concentration and distribution profile of fuel in reacting case are enlarged as well. When fuel temperature is raised from 350K to 550K, the peak value of droplet evaporation rate at the vicinity of nozzle is increased by 26.7 times, the uniformity index downstream of the primary recirculation zone (PRZ) is increased by 2.57%, the axial length and maximum negative axial velocity of PRZ are reduced by 13% and 21%. The average temperature and NO emission at combustor outlet are increased by 1.99% and 48.15%, the mass fraction of CO is decreased by 5.45%. Besides, the number, diameter, and distribution space of droplets are decreased sharply. The formation of premixed flame and propagation of high-temperature region are promoted, the flame front is changed from a conical shape to a recessed shape. The combustion efficiency can be improved by increasing fuel temperature. The present study is expected to provide insightful information for understanding characteristics of LDI combustor with elevated fuel temperatures.

Modeling of Particle Wall Interaction and Film Transport Using Eulerian Wall Film Model

2014 ◽  
Author(s):  
Rahul Ingle ◽  
Ravi Yadav ◽  
Hemant Punekar ◽  
Jing Cao
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Continuous Phase ◽  
Pollutant Emissions ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Secondary Atomization ◽  
Wall Film ◽  
Wall Interaction

The growing awareness of pollutant emissions from gas turbines has made it very important to study fuel atomization system, the spray wall interaction and hydrodynamic of film formed on engine walls. A precise fuel spray spatial distribution and efficient fuel air mixing plays important role in improving combustion performance. Cross-flow injection and film atomization technique has been studied extensively for gas turbine engines to achieve efficient combustion. Air blast atomizer is one of these kind of systems used in gas turbine engines which involves shear driven prefilmer secondary atomization. In addition to gas turbine combustor shear driven liquid wall film can be seen in IC engines, rocket nozzles, heat exchangers and also on steam turbine blades. In our work we have used Eulerian Wall Film (EWF) [1] model to simulate the experiment performed by Arienti et al. [2]. In the Arienti’s experiment liquid jet is injected from a nozzle from the top of the chamber. Droplets shed from the jet surface due to primary and later secondary atomization in the presence of high shearing cross flowing air. Further liquid fuel particles hit the wall to form film, film moves subjected to shear from the gas phase. Liquid film can reatomizes due to subgrid processes like stripping, splashing and film breakup. In current study we have validated Arienti et al. [2] experimental data by modeling complex & coupled physics of spray, film and continuous phase and by accounting complex subgrid processes.

Effects of Periodic Inflow Unsteadiness on the Time-Averaged Velocity Field and Pressure Recovery of a Diffusing Bend With Strong Curvature

2004 ◽  
Vol 126 (2) ◽  
pp. 229-237 ◽  
Author(s):  
M. I. Yaras ◽  
P. Orsi
Keyword(s):  
Velocity Field ◽  
Gas Turbine ◽  
Large Scale ◽  
Cross Flow ◽  
Operating Conditions ◽  
Pressure Recovery ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Cross Sectional ◽  
Data Set

This study examines the effects of periodic inflow unsteadiness on the flow development through fishtail-shaped diffusers utilized on small gas-turbine engines. In this application, periodic unsteadiness is caused by a jet-wake type of flow discharging from each passage of the centrifugal compressor impeller. The study consists of detailed measurements in a large-scale fishtail diffuser rig with a geometry that is typical of those used in small gas-turbine engines. Measurements of the transient velocity field have been performed at five cross-sectional planes throughout the diffuser using a miniature hot-wire probe with four wires. These measurements involve frequencies of inflow unsteadiness corresponding to design as well as off-design operating conditions. Results indicate significant effects of inflow unsteadiness at the low end of the tested frequencies on the time-averaged streamwise and cross-flow velocity fields in the diffuser. This is shown to translate into a notable impact on the pressure recovery. In addition to providing insight into the physics of this flow, the experimental results presented here constitute a detailed and accurate data set that can be used to validate computational-fluid-dynamics algorithms for this type of flow.

A Comprehensive Fuel Spray Model for High Pressure Fuel Injectors

2008 ◽  
Author(s):  
Gerald J. Micklow ◽  
Krishna Ankem ◽  
Tarek Abdel-Salam
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Gas Turbine ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection Pressure ◽  
Pollutant Emission ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Fuel Injectors

Understanding the physics and chemistry involved in spray combustion, with its transient effects and the inhomogeneity of the spray is quite challenging. For efficient operation of both internal combustion and gas turbine engines, great insight into the physics of the problem can be obtained when a computational analysis is used in conjunction with either an experimental program or through published experimental data. The main area to be investigated to obtain good combustion begins with the fuel injection process and an accurate description of the mean diameter of the fuel particle, injection pressure, drag coefficient, rate shaping etc must be defined correctly. This work presents a methodology to perform the task set out in the previous paragraph and uses experimental data obtained from available literature to construct a semi-empirical numerical model for high pressure fuel injectors. A modified version of a multidimensional computer code called KIVA3V was used for the computations, with improved sub-models for mean droplet diameter, injection pressure, injection velocity, and drop distortion and drag. The results achieved show good agreement with the published in-cylinder experimental data for a Volkswagen 1.9 L turbo-charged direct injection internal combustion engine under actual operating conditions. It is crucial to model the spray distribution accurately, as the combustion process and the resulting temperature distribution and pollutant emission formation is intimately tied to the in-cylinder fuel distribution. The present scheme has achieved excellent agreement with published experimental data and will make an important contribution to the numerical simulation of the combustion process and pollutant emission formation in compression ignition direct injection engines and gas turbine engines.

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