Investigation of the Fuel Distribution in a Shockless Explosion Combustor

2021 ◽  
Author(s):  
Fatma Cansu Y\xe3\xbcCel ◽  
Fabian Habicht ◽  
Finn Lueckoff ◽  
Alexander Jaeschke ◽  
Kilian Oberleithner ◽  
...  
Keyword(s):  
Fuel Distribution

Influence of Main Swirler Vane Angle on the Ignition Performance of TeLESS-II Combustor

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Bo Wang ◽  
Chi Zhang ◽  
Yuzhen Lin ◽  
Xin Hui ◽  
Jibao Li
Keyword(s):  
High Speed ◽  
Inlet Temperature ◽  
Main Stage ◽  
Ignition Process ◽  
High Speed Camera ◽  
Fuel Distribution ◽  
Fuel Droplets ◽  
Planar Laser ◽  
Cfd Method ◽  
Vane Angle

In order to balance the low emission and wide stabilization for lean premixed prevaporized (LPP) combustion, the centrally staged layout is preferred in advanced aero-engine combustors. However, compared with the conventional combustor, it is more difficult for the centrally staged combustor to light up as the main stage air layer will prevent the pilot fuel droplets arriving at igniter tip. The goal of the present paper is to study the effect of the main stage air on the ignition of the centrally staged combustor. Two cases of the main swirler vane angle of the TeLESS-II combustor, 20 deg and 30 deg are researched. The ignition results at room inlet temperature and pressure show that the ignition performance of the 30 deg vane angle case is better than that of the 20 deg vane angle case. High-speed camera, planar laser induced fluorescence (PLIF), and computational fluids dynamics (CFD) are used to better understand the ignition results. The high-speed camera has recorded the ignition process, indicated that an initial kernel forms just adjacent the liner wall after the igniter is turned on, the kernel propagates along the radial direction to the combustor center and begins to grow into a big flame, and then it spreads to the exit of the pilot stage, and eventually stabilizes the flame. CFD of the cold flow field coupled with spray field is conducted. A verification of the CFD method has been applied with PLIF measurement, and the simulation results can qualitatively represent the experimental data in terms of fuel distribution. The CFD results show that the radial dimensions of the primary recirculation zone of the two cases are very similar, and the dominant cause of the different ignition results is the vapor distribution of the fuel. The concentration of kerosene vapor of the 30 deg vane angle case is much larger than that of the 20 deg vane angle case close to the igniter tip and along the propagation route of the kernel, therefore, the 30 deg vane angle case has a better ignition performance. For the consideration of the ignition performance, a larger main swirler vane angle of 30 deg is suggested for the better fuel distribution when designing a centrally staged combustor.

scholarly journals Improving Blowout Performance of the Conical Swirler Combustor by Employing Two Parts of Fuel at Low Operating Condition

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1681
Author(s):  
Yixiang Yuan ◽  
Qinghua Zeng ◽  
Jun Yao ◽  
Yongjun Zhang ◽  
Mengmeng Zhao ◽  
...  
Keyword(s):  
Distribution Ratio ◽  
Performance Enhancement ◽  
Experimental Testing ◽  
Stability Boundary ◽  
Operating Conditions ◽  
Nox Emission ◽  
Combustion Stability ◽  
Gas Temperature ◽  
Contact Ratio ◽  
Fuel Distribution

Aiming at the problem of the narrow combustion stability boundary, a conical swirler was designed and constructed based on the concept of fuel distribution. The blowout performance was studied at specified low operating conditions by a combination of experimental testing and numerical simulations. Research results indicate that the technique of the fuel distribution can enhance the combustion stability and widen the boundary of flameout within the range of testing conditions. The increase of the fuel distribution ratio improves the combustion stability but leads to an increase in NOx emission simultaneously. The simulation results show the increase of the fuel distribution ratio causes contact ratio increase in the area of lower reference velocity and gas temperature increase. The increased contact ratio and temperature contribute to the blowout performance enhancement, which is identical to the analysis result of the Damkohler number. The reported work in this paper has potential application value for the development of an industrial burner and combustor with high stability and low NOx emission, especially when the combustion system is required to be stable and efficient at low working conditions.

Dual-Location Fuel Injection Effects on Emissions and NO*/OH* Chemiluminescence in a High Intensity Combustor

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Ahmed O. Said ◽  
Ahmed E. E. Khalil ◽  
Ashwani K. Gupta
Keyword(s):  
Fuel Injection ◽  
Single Injection ◽  
Mixing Time ◽  
Fuel Mixture ◽  
Combustion Noise ◽  
Fuel Distribution ◽  
Mixture Preparation ◽  
Pollutants Emission ◽  
Fuel Mixing ◽  
Colorless Distributed Combustion

Colorless distributed combustion (CDC) has shown to provide ultra-low emissions of NO, CO, unburned hydrocarbons, and soot, with stable combustion without using any flame stabilizer. The benefits of CDC also include uniform thermal field in the entire combustion space and low combustion noise. One of the critical aspects in distributed combustion is fuel mixture preparation prior to mixture ignition. In an effort to improve fuel mixing and distribution, several schemes have been explored that includes premixed, nonpremixed, and partially premixed. In this paper, the effect of dual-location fuel injection is examined as opposed to single fuel injection into the combustor. Fuel distribution between different injection points was varied with the focus on reaction distribution and pollutants emission. The investigations were performed at different equivalence ratios (0.6–0.8), and the fuel distribution in each case was varied while maintaining constant overall thermal load. The results obtained with multi-injection of fuel using a model combustor showed lower emissions as compared to single injection of fuel using methane as the fuel under favorable fuel distribution condition. The NO emission from double injection as compared to single injection showed a reduction of 28%, 24%, and 13% at equivalence ratio of 0.6, 0.7, and 0.8, respectively. This is attributed to enhanced mixture preparation prior to the mixture ignition. OH* chemiluminescence intensity distribution within the combustor showed that under favorable fuel injection condition, the reaction zone shifted downstream, allowing for longer fuel mixing time prior to ignition. This longer mixing time resulted in better mixture preparation and lower emissions. The OH* chemiluminescence signals also revealed enhanced OH* distribution with fuel introduced through two injectors.

Measurement of Biodiesel Blend and Conventional Diesel Spray Structure Using X-Ray Radiography

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
A. L. Kastengren ◽  
C. F. Powell ◽  
K.-S. Im ◽  
Y.-J. Wang ◽  
J. Wang
Keyword(s):  
Cone Angle ◽  
Injection Pressure ◽  
Fuel Distribution ◽  
X Ray ◽  
Spray Structure ◽  
Quantitative Measurements ◽  
Biodiesel Blend ◽  
Temporal And Spatial ◽  
Nozzle Geometries ◽  
Fuel Effects

The near-nozzle structure of several nonevaporating biodiesel-blend sprays has been studied using X-ray radiography. Radiography allows quantitative measurements of the fuel distribution in sprays to be made with high temporal and spatial resolution. Measurements have been made at different values of injection pressure, ambient density, and with two different nozzle geometries to understand the influences of these parameters on the spray structure of the biodiesel blend. These measurements have been compared with corresponding measurements of Viscor, a diesel calibration fluid, to demonstrate the fuel effects on the spray structure. Generally, the biodiesel-blend spray has a similar structure to the spray of Viscor. For the nonhydroground nozzle used in this study, the biodiesel-blend spray has a slightly slower penetration into the ambient gas than the Viscor spray. The cone angle of the biodiesel-blend spray is generally smaller than that of the Viscor spray, indicating that the biodiesel-blend spray is denser than the Viscor spray. For the hydroground nozzle, both fuels produce sprays with initially wide cone angles that transition to narrow sprays during the steady-state portion of the injection event. These variations in cone angle with time occur later for the biodiesel-blend spray than for the Viscor spray, indicating that the dynamics of the injector needle as it opens are somewhat different for the two fuels.

A Quasi-Dimensional Fuel Distribution Model for a Radially Stratified Engine

2021 ◽  
Author(s):  
Dennis Robertson ◽  
Patrick O'Donnell ◽  
Benjamin Lawler ◽  
Robert Prucka
Keyword(s):  
Reference Model ◽  
Computation Time ◽  
Distribution Model ◽  
Strategy Development ◽  
Real Time Control ◽  
Spray Penetration ◽  
Fuel Distribution ◽  
Time Control ◽  
Fuel Stratification ◽  
Execution Speed

Abstract Several combustion strategies leverage radial fuel stratification to adapt combustion performance between the center of the chamber and the outer regions independently. Spark-assisted compression ignition (SACI) relies on careful tuning of this radial stratification to maximize the combined performance of flame propagation and autoignition. Established techniques for determining in-cylinder fuel stratification are computationally intensive, limiting their feasibility for control strategy development and real-time control. A simplified model for radial fuel stratification is developed for control-oriented objectives. The model consists of three submodels: spray penetration, fuel distribution along the spray axis, and post-injection mixing. The spray penetration model is adapted from fuel spray models presented in the literature. The fuel distribution and mixing submodels are validated against injection spray results from an LES 3-D computational fluid dynamics (CFD) reference model for three test points as a function of crank angle. The quasi-one-dimensional model matches the CFD results with a root mean square error (RMSE) for equivalence ratio of 0.08?0.11. This is a 50% reduction from the 0.16?0.20 RMSE for a model that assumes a uniform fuel distribution immediately after injection. The computation time is 230 ms on an Intel Xeon E5-1620 v3 to solve each case without significant optimization for code execution speed.

Long-Life Base Load Service at 1600 F Turbine Inlet Temperature

1967 ◽  
Vol 89 (1) ◽  
pp. 41-46 ◽  
Author(s):  
N. E. Starkey
Keyword(s):  
Inlet Temperature ◽  
Air Cooling ◽  
Turbine Inlet Temperature ◽  
Fuel Distribution ◽  
Design Considerations ◽  
Turbine Inlet ◽  
Accurate Temperature ◽  
Long Life ◽  
Accurate Temperature Control ◽  
Base Load

Design considerations required for base load long-life service at turbine inlet temperature above 1600 F are discussed. These include control of combustion profile, air cooling of the first-stage nozzle, long-shank turbine buckets, accurate air and fuel distribution, and accurate temperature control.

Simultaneous Spectral Imaging of C2*/CH* at Low-to-High Pressure Combustion

2017 ◽  
Author(s):  
Jonathan Reyes ◽  
Kareem Ahmed
Keyword(s):  
Intensity Ratio ◽  
High Pressures ◽  
Diffusion Flames ◽  
Laminar Flames ◽  
Great Promise ◽  
Fuel Distribution ◽  
Premixed Laminar ◽  
The Cost ◽  
Indexing Technique ◽  
First Time

This paper presents the correlation of the intensity ratio of the C2* and CH* radicals to fuel-air measurements over a range of pressures using 93% octane gasoline as the fuel. The measurements are conducted for the first time at high pressures. The study utilizes beam splitting technology to simultaneously view C2* and CH* as a line of sight, global measurement at the cost of resolution. A heavily instrumented constant volume combustor, with optical access, was employed to acquire the data. The ratio of C2* and CH* has been proven to be a good index of the equivalence ratio of premixed laminar flames. This index is attained, quite simply, by filtering each at their respected emissive peaks and taking the ratio of C2* over CH*. This technique shows great promise for use in turbomachinery as it will allow for identification of rich and lean locations in a combustor. By knowing the fuel-air field, combustor inefficiencies can be addressed to allow for greater energy release in combustion. The issue lies with the application of the indexing technique. Presented data to date has been performed on laboratory based diffusion flames exhausting to atmosphere, or premixed, steady, combustor type flames at low pressure (1atm) conditions. These types of flames are not relevant for engine combustor conditions. Understanding the fuel distribution at relevant regimes will reveal where inefficiencies may lie in injector or combustor design. Propagating flame kernels pose a problem in that they do not produce as much light as a steady flame, this makes spectral data difficult to obtain. Steady flames also do not address the effects that pressure may have on the index of C2* and CH*. The authors of this work seek to address three main issues associated with the indexing technique: The feasibility of its application to combustors (hardware design), The ability to operate at low-light ignition events, and the effects pressure may have on the correlation of intensity ratio to the fuel-air measurement.

Sign in / Sign up

Export Citation Format

Share Document