Numerical Investigation of the Influence of Flow Parameters Nonuniformity at the Diffuser Inlet on Characteristics of the GTE Annular Combustion Chamber

2015 ◽  
Author(s):  
Sergey S. Matveev ◽  
Ivan A. Zubrilin ◽  
Mikhail Yu. Orlov ◽  
Sergey G. Matveev
Keyword(s):  
Combustion Chamber ◽  
Dynamic Pressure ◽  
Air Distribution ◽  
Gas Generator ◽  
Air Velocity ◽  
Degree Polynomial ◽  
Flow Dynamic ◽  
Ansys Fluent ◽  
Flow Parameters ◽  
Mode Of Operation

Parameters at a combustion chamber’s inlet significantly vary in an aircraft engine’s transient states of operation. At the same time, there is a significant spatial heterogeneity of flow parameters at a diffuser inlet of a combustion chamber, which is defined by nature of flow in a compressor and an individual for each mode of operation of a specific gas generator. In this paper presented a study of an influence of radial and circumferential nonuniformities of flow parameters on characteristics of a combustion chamber. Multi spray for annular combustion chamber with two rows of burner is considered. Z-shaped sector, which contains two nozzles of outer and two nozzles of inner row, was selected as the calculated domain. Calculations were carried out in ANSYS Fluent 14.5 software package with an implementation of cluster analysis. Nonuniformity at a diffuser inlet was set as fifth degree polynomial, which was derived from a numerical simulation of a compressor. As a result it was established, that radial nonuniformity of flow parameters at an inlet of a combustion chamber influences on characteristics of a combustion chamber. A stretched shape of velocity profile contributes to higher air flow dynamic pressure on dome than using uniform profile air velocity. At that, local equivalents ratio excess are changing, and consequently, sizes and location NOx production zones are changing as well. The residual rotation of flow from the compressor leads to a lesser effect on total pressure drop and air distribution in flame tube. The obtained results showed that, during a design of a combustion chamber, it is necessary to take into account nonuniformity of parameters’ distribution at its inlet.

scholarly journals Unsteady RANS Simulation of Air Distribution in a Ventilated Classroom with Numerous Jets

2019 ◽  
Vol 111 ◽  
pp. 02010
Author(s):  
Nikolay Ivanov ◽  
Marina Zasimova ◽  
Evgueni Smirnov ◽  
Alexey Abramov ◽  
Detelin Markov ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Velocity Field ◽  
Flow Structure ◽  
Air Distribution ◽  
Air Velocity ◽  
3D Flow ◽  
Ansys Fluent ◽  
Test Conditions ◽  
Rectangular Form ◽  
Unsteady Rans

The study is devoted to the Unsteady Reynolds-Averaged Navies-Stokes (URANS) simulation of ventilation in an isothermal room with numerous jets supplied from ceiling diffusers. The computations of the airflow under the test conditions considered were carried out in the classroom of the Technical University of Sofia with no occupants. The room floor has a simple rectangular form, but several columns, beams, window sills, and four radiators are located inside the room that makes the geometry more complex. Air is supplied to the room through four ceiling fan coils, the Reynolds number is 2×104. Calculations were carried out using the ANSYS Fluent 18.2 software with the standard k-ε turbulence model chosen. Computational meshes of up to 33 million hexahedral cells clustered to the inlet and outlet sections were used. The main aim of the study presented is to analyze and discuss the complicated 3D flow structure in the room and to give foundation for future measurements of air velocity field in the room.

Numerical assessment on the performance of variable area single- and two-stage ejectors: A comparative study

2021 ◽  
pp. 095440892110331
Author(s):  
Anil Kumar ◽  
Virendra Kumar ◽  
PMV Subbarao ◽  
Surendra K Yadav ◽  
Gaurav Singhal
Keyword(s):  
Change Theory ◽  
Single Stage ◽  
Two Stage ◽  
Entrainment Ratio ◽  
Ansys Fluent ◽  
One Dimensional ◽  
Flow Parameters ◽  
Constant Rate ◽  
Numerical Assessment ◽  
The One

The two-stage ejector has been suggested to replace the single-stage ejector geometrical configuration better to utilize the discharge flow’s redundant momentum to induce secondary flow. In this study, the one-dimensional gas dynamic constant rate of momentum change theory has been utilized to model a two-stage ejector along with a single-stage ejector. The proposed theory has been utilized in the computation of geometry and flow parameters of both the ejectors. The commercial computational fluid dynamics tool ANSYS-Fluent 14.0 has been utilized to predict performance and visualize the flow. The performance in terms of entrainment ratio has been compared under on- design and off-design conditions. The result shows that the two-stage ejector configuration has improved (≈57%) entrainment capacity than the single-stage ejector under the on-design condition.

A Preliminary Study of the Blade Erosion for a Wind Turbine Operating in a Dusty Environment

2016 ◽  
Author(s):  
Ahmed Hossam El-Din ◽  
Aya Diab
Keyword(s):  
Leading Edge ◽  
Particle Collision ◽  
Turbine Engines ◽  
Surface Erosion ◽  
Coal Slurry ◽  
Predictive Tool ◽  
Ansys Fluent ◽  
Flow Parameters ◽  
Discrete Phase Modeling ◽  
Discrete Phase

The process of surface erosion due to particle collision has been the focus of a number of investigations with regards to gas turbine engines, aircraft, reentry missiles, pipelines carrying coal slurry, etc. Recently, increased interest in wind energy by countries in the Saharan regions of the Middle East and North Africa (MENA) brings about some concern about leading edge erosion of wind turbines operating under such dusty conditions. Leading edge erosion can have a detrimental impact on the extracted energy as it changes the blade surface roughness causing premature/unpredictable separation. Though erosion may not be easily avoided; it may be mitigated via using airfoil families characterized by low roughness sensitivity. In this paper, a model of an airfoil erosion subjected to sand blasting is developed using the discrete phase modeling capability in ANSYS-FLUENT along with the DNV erosion model. The effect of various flow parameters, such as angle of attack, and particle size, on the extent of erosion is investigated for a number of airfoil designs. The developed model is used as a predictive tool to assess the power deterioration of eroded wind blades.

Experimental Measurements Research on Internal Micro-Environment of Individually Ventilated Cage System

2013 ◽  
Vol 401-403 ◽  
pp. 1044-1047
Author(s):  
Dong Xie ◽  
Shun Quan Mo
Keyword(s):  
Laboratory Animal ◽  
Close Correlation ◽  
National Standards ◽  
Air Distribution ◽  
Experimental Measurements ◽  
Internal Environment ◽  
Air Velocity ◽  
Cage System ◽  
Environment Parameters ◽  
Edge Side

This paper firstly presents the operation principle of individually ventilated cages (IVC) system. Measurements on micro-environment of IVC system in laboratory animal room at University of South China are conducted to attain the internal environment parameters (Temperature, humidity, air velocity, air cleanliness and noise). Research results show that internal micro-environment parameters basically meet national standards about the barrier environment, but internal air distribution is uneven. In IVC system, air velocities in the edge side are higher than in the middle side, and the maximum air velocity is about 10% larger than the minimum value. Temperature in internal micro-environment depends on indoor temperatures which IVC system located in, and there has a close correlation between air velocity and temperatures. Internal environment evaluation could provide the first-hand research materials for guiding the breeding and management of laboratory animal.

MATHEMATICAL MODEL OF TWO-DIMENSIONAL LAYERED PRESSURE FLOW IN THE AUGER CHANNEL

2018 ◽  
Author(s):  
А.В. ГУКАСЯН ◽  
В.С. КОСАЧЕВ ◽  
Е.П. КОШЕВОЙ
Keyword(s):  
Mathematical Model ◽  
Analytical Solution ◽  
Cross Section ◽  
Dynamic Pressure ◽  
Two Dimensional ◽  
Flow Dynamic ◽  
Pressure Flow ◽  
Rectangular Channels ◽  
Wide Range ◽  
Pressure Characteristics

Получено аналитическое решение двумерного слоистого напорного течения в канале шнека, позволяющее моделировать расходно-напорные характеристики прямоугольных каналов шнековых прессов с учетом гидравлического сопротивления формующих устройств и рассчитывать расходно-напорные характеристики экструдеров в широком диапазоне геометрии витков как в поперечном сечении, так и по длине канала. Obtained the analytical solution of two-dimensional layered pressure flow in the screw channel, allow to simulate the flow-dynamic pressure characteristics of rectangular channels screw presses taking into account the hydraulic resistance of the forming device and calculate the mass flow-dynamic pressure characteristics of the extruders in a wide range of the geometry of the coils, as in its cross section and along the length of the channel.

Experimental Modeling of Air Temperature and Velocity Distribution in an Engine Compartment

2006 ◽  
Author(s):  
A. A. Mozafari ◽  
M. H. Saidi ◽  
J. Neyestani ◽  
A. E. Sany
Keyword(s):  
Heat Transfer ◽  
Velocity Distribution ◽  
Air Temperature ◽  
Gasoline Engine ◽  
Point Of View ◽  
Vehicle Body ◽  
Air Distribution ◽  
Wind Effect ◽  
Engine Compartment ◽  
Air Velocity

Investigation of air distribution and wind effect on a vehicle body from the point of view of underhood heat transfer effect and proper positioning of vehicle elements such cooler, condenser and engine configuration is an important area for engine researchers and manufacturers as well. In this research, the effect of air velocity distribution and wind effect around a vehicle is simulated and temperature and velocity distribution around engine block which is influenced by the wind effect is investigated. Thermal investigation of the engine compartment components is performed using results of underhood air temperature and velocity distribution. The heat transfer from engine surface is calculated from the engine energy balance in which their input data are obtained from a comprehensive experimental study on a four cylinder gasoline engine.

A Novel Gas Generator Concept for Jet Engines Using a Rotating Combustion Chamber

2013 ◽  
Author(s):  
Peter Jeschke ◽  
Andreas Penkner
Keyword(s):  
Combustion Chamber ◽  
Weight Ratio ◽  
Thermodynamic Cycle ◽  
Ceramic Materials ◽  
Single Stage ◽  
Jet Engines ◽  
Gas Generator ◽  
Small Core ◽  
Efficiency Increase ◽  
Flow Compressor

A gas generator — consisting of a single-stage shrouded mixed-flow compressor without a diffusor, a rotating combustion chamber, and a vaneless single-stage shrouded centripetal turbine — is presented and analyzed here. All components comprise a coherent rotating device, which avoids most of the problems usually associated with small gas generators. In other words, the concept avoids all radial clearances, it is vaneless, shortens the combustion chamber, minimizes the wetted area and enables ceramic materials to be used, due to compressive blade stresses. However, the concept faces severe structural, thermal and chemical reaction challenges. All these features and their implications are discussed and their benefits for several jet engines are quantified, mainly by means of thermodynamic cycle calculations. An upfront CFD analysis identifies a polytropic compressor efficiency of around 95%. It is then demonstrated that the concept offers a thrust-to-weight ratio which is several times higher than the standard when incorporated into small UAV-type jet engines. It also enables an attractive multistage and dual-flow, but fully vaneless design option. Lastly, a thermal efficiency increase of several percentage points would be achieved, if the concept were to be realized in the (small) core of turbofans with highest overall pressure ratios and high bypass ratios. In summary, the paper presents a gas generator approach which may be considered by designers of small jet engines like those used in UAV applications and it might even be a (challenging) long-term option for the small core engines encountered in future turbofans and turboprops.

scholarly journals Optimization of guide vane positions in bended inflow of mechanical draft wet-cooling tower

2011 ◽  
Vol 32 (3) ◽  
pp. 263-272
Author(s):  
Adam Klimanek ◽  
Tomasz Musioł ◽  
Adam Stechman
Keyword(s):  
Standard Deviation ◽  
Velocity Distribution ◽  
Objective Function ◽  
Cooling Tower ◽  
Guide Vane ◽  
Optimization Procedure ◽  
Cfd Model ◽  
Air Velocity ◽  
Ansys Fluent ◽  
Flow Solver

Optimization of guide vane positions in bended inflow of mechanical draft wet-cooling tower Optimization of vane positions in a mechanical draft wet-cooling tower is presented in this paper. The originally installed, equally spaced, vanes produced non-uniform air velocity distribution reducing the performance of the fill of the cooling tower. A 2D CFD model of the tower has been created. The model has then been used to determine the objective function in the optimization procedure. The selected objective function was the standard deviation of the velocity of air entering the fill. The Goal Driven Optimization tools of the ANSYSWorkbench 2.0 have been used for the optimization and the ANSYS Fluent 13.0 as a flow solver. The optimization allowed reduction of the objective function and producing a more uniform air flow.

CFD Analysis of the Primary Side in a Helical-Coil Once-Through Steam Generator

2017 ◽  
Author(s):  
Kai Ye ◽  
Yaoli Zhang ◽  
Jianshu Lin ◽  
Ning Li ◽  
Yinglin Yang ◽  
...  
Keyword(s):  
Steam Generator ◽  
Nuclear Power ◽  
Rational Design ◽  
Large Scale ◽  
Three Dimensional ◽  
Helical Coil ◽  
Complicated Structure ◽  
Ansys Fluent ◽  
Flow Parameters ◽  
Computational Fluid Dynamics Cfd

The helical-coil once-through steam generator (OTSG) is usually used in the nuclear power plant when the compactness of equipment was taken into consideration. The investigation of flow parameters in the primary side is valuable for the optimization of the OTSG. The purpose of this research is to obtain a further understanding of fluid behaviors in the primary side of the OTSG to achieve a more rational design. Using ANSYS ICEM and ANSYS FLUENT, a three-dimensional (3D) computational fluid dynamics (CFD) model was created and analyzed. Through a series of cases, the velocity profiles and pressure drop through the primary side of the helical-coil OTSG have been calculated, and the influences of different structure designs on the coolant flow parameters have also been tested. Ultimately some pertinent suggestions for improvements were proposed, and insight is obtained into the importance of various modeling considerations in such a model with a complicated structure and large-scale grids.

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