scholarly journals CFD Analysis and NOx Prediction in H2 and Ch4 Turbulent Non-premixed Flame Compared with Swirling Flame

2021 ◽  
Vol 20 (2) ◽  
pp. 101-106
Author(s):  
Ahmed Benali ◽  
Bellaouar Abderrahmane ◽  
Lalmi Djemoui ◽  
Hadef Redjem
Keyword(s):  
Turbulent Combustion ◽  
Combustion Process ◽  
Cylindrical Shape ◽  
Cfd Analysis ◽  
Ansys Fluent ◽  
Mass Fractions ◽  
Calculation Results ◽  
Swirling Flame ◽  
Pdf Model ◽  
The Comparative Study

This work is devoted to the comparative study for the formation and dissociation of nitrogen oxides by the numerical simulation of turbulent combustion without premix in a combustion chamber having a cylindrical shape with two coaxial jets, two flames using the ANSYS fluent software16.0. The study focuses on the influence of the type of fuel on the composition of discharges in content with NOx, that is to say two cases are treated and compared. Turbulence is modeled by the k-ε model and the chemical aspect of combustion is treated by the PDF model for each flame. The calculation results relate to the characteristics of dynamic fields, temperature, the mass fractions of different species involved in the combustion process and the NOx prediction. The effect of the swirl is also tested in this study with a CFD prediction of non premixed swirling g flame. These results are compared with measurements and confrontations is satisfactory.

scholarly journals Dehumidification Performance of LiCl in Falling Film Type Liquid Desiccant Dehumidifier

2019 ◽  
Vol 8 (6) ◽  
pp. 3093-3099
Keyword(s):  
Water Vapor ◽  
Transport Model ◽  
Cfd Analysis ◽  
Falling Film ◽  
Moist Air ◽  
Dimensional Model ◽  
Liquid Desiccant ◽  
Ansys Fluent ◽  
Film Type ◽  
Mass Fractions

In the present study, CFD analysis of falling film type liquid desiccant dehumidifier is carried out to predict its performance In these simulations it is studied how the flow pattern of liquid desiccant effects the interaction between the moist air and the liquid desiccant.Two dimensional model was simulated by using the software ANSYS (FLUENT). The volume of fluid (VOF) was selected as the multiphase method for the simulation process. The water vapor/humidity content in the air is given by using species transport model and the variation of amount of water hold by the air is simulated. The liquid desiccant considered for study is LiCl with 30% concentration and the mass fraction of water vapor used in air is varied from 0.01 to 0.02. The properties of LiCl at 30% concentration were calculated and inlet parameters of air and desiccant are fed to the software as input. The model was subjected to different inlet mass fractions and determined the dehumidification effectiveness.

Experimental and Numerical Analysis of a Motorcycle Air Intake System Aerodynamics and Performance

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
M. A. Abd Halim ◽  
N. A. R. Nik Mohd ◽  
M. N. Mohd Nasir ◽  
M. N. Dahalan
Keyword(s):  
Combustion Process ◽  
Three Dimensional ◽  
Engine Performance ◽  
Internal Flow ◽  
Rapid Expansion ◽  
Navier Stokes ◽  
Turbulent Fluctuation ◽  
Ansys Fluent ◽  
Induction System ◽  
Acceleration And Deceleration

Induction system or also known as the breathing system is a sub-component of the internal combustion system that supplies clean air for the combustion process. A good design of the induction system would be able to supply the air with adequate pressure, temperature and density for the combustion process to optimizing the engine performance. The induction system has an internal flow problem with a geometry that has rapid expansion or diverging and converging sections that may lead to sudden acceleration and deceleration of flow, flow separation and cause excessive turbulent fluctuation in the system. The aerodynamic performance of these induction systems influences the pressure drop effect and thus the engine performance. Therefore, in this work, the aerodynamics of motorcycle induction systems is to be investigated for a range of Cubic Feet per Minute (CFM). A three-dimensional simulation of the flow inside a generic 4-stroke motorcycle airbox were done using Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) solver in ANSYS Fluent version 11. The simulation results are validated by an experimental study performed using a flow bench. The study shows that the difference of the validation is 1.54% in average at the total pressure outlet. A potential improvement to the system have been observed and can be done to suit motorsports applications.

Effect of pipe expansion on the redistribution of residual stresses after molding

2020 ◽  
Vol 10 (2) ◽  
pp. 122-126
Author(s):  
Nikolay A. Makhutov ◽  
◽  
Dmitry A. Neganov ◽  
Eugeny P. Studenov ◽  
◽  
...  
Keyword(s):  
Residual Stresses ◽  
Strain Distribution ◽  
Strain State ◽  
Stress And Strain ◽  
Cylindrical Shape ◽  
Pipe Material ◽  
Pipe Expansion ◽  
Calculation Results ◽  
Residual Deformations ◽  
Stress And Strain Distribution

In the factory, pipes for trunk oil and oil product pipelines are obtained by molding and welding. To ensure a cylindrical shape and reduce technological residual stresses, expansion technology is used. Pipe expansion causes a significant change in the values of residual deformations and stresses. The article presents both the calculation results and graphs regarding stress and strain distribution during bending of the stock and their redistribution after expansion. Based on the calculation results, the final total values of residual stresses and residual deformations caused by bending and expansion were stated to be important components of the stress-strain state observed in pipelines being operated under cyclic loading, as well as those used in assessing how degradation affects the ductility of the pipe material. These factors were concluded as being reasonably taken into account when performing verification calculations regarding long-running pipelines if, based on their diagnostics and analysis, their state does not meet modern strength requirements.

Study of the Change of Performance of an Elastic Vertical Hydrofoil With Deformation

2014 ◽  
Author(s):  
Alexander Führing ◽  
Subha Kumpaty ◽  
Chris Stack
Keyword(s):  
Water Flow ◽  
Lift Coefficient ◽  
Flow Analysis ◽  
Turbulence Models ◽  
Flow Property ◽  
Performance Data ◽  
Cfd Analysis ◽  
Ansys Fluent ◽  
Drag Forces ◽  
Fluid Flow Analysis

In external and internal fluid flow analysis using numerical methods, most attention is paid to the properties of the flow assuming absolute rigidity of the solid bodies involved. However, this is often not the case for water flow or other fluids with high density. The pressure forces cause the geometry to deform which in turn changes the flow properties around it. Thus, a one-way and two-way Fluid-Structure Interaction (FSI) coupling is proposed and compared to a CFD analysis of a windsurfing fin in order to quantify the differences in performance data as well as the properties of the flow. This leads to information about the necessity of the use of FSI in comparison to regular CFD analysis and gives indication of the value of the enhanced results of the deformable analysis applied to water flow around an elastically deformable hydrofoil under different angles of attack. The performance data and flow property evaluation is done in ANSYS Fluent using the k-ω SST and k-ε model with a y+ of 1 and 35 respectively in order to be able to compare the behavior of both turbulence models. It is found that the overall lift coefficient in general is lower and that the flow is less turbulent because of softer transition due to the deformed geometry reducing drag forces. It is also found that the deformation of the tip of the hydrofoil leads to vertical lift forces. For the FSI analysis, one-way and two-way coupling were incorporated leading to the ability to compare results. It has been found that one-way coupling is sufficient as long as there is no stall present at any time.

Numerical study of the aerodynamic and power characteristics of the cycloidal rotor, under incoming flow

2019 ◽  
pp. 25-34
Author(s):  
Александр Анатольевич Дектерев ◽  
Артем Александрович Дектерев ◽  
Юрий Николаевич Горюнов
Keyword(s):  
Flow Velocity ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
Incoming Flow ◽  
Ansys Fluent ◽  
Energy Characteristics ◽  
Power Characteristics ◽  
Calculation Results

Исследование направлено на разработку и апробацию методики численного моделирования аэродинамических и энергетических характеристик циклоидального ротора. За основу взята конфигурация ротора IAT21 L3. Для нее с использованием CFD-пакета ANSYS Fluent построена математическая модель и выполнен расчет. Проанализировано влияние скорости набегающего потока воздуха на движущийся ротор. Математическая модель и полученные результаты исследования могут быть использованы при создании летательных аппаратов с движителями роторного типа. This article addresses the study of the aerodynamic and energy characteristics of a cycloidal rotor subject to the influence of the incoming flow. Cycloidal rotor is one of the perspective devices that provide movement of aircrafts. Despite the fact that the concept of a cycloidal rotor arose in the early twentieth century, the model of a full-scale aircraft has not been yet realized. Foreign scientists have developed models of aircraft ranging in weight from 0.06 to 100 kg. The method of numerical calculation of the cycloidal rotor from the article [1] is considered and realized in this study. The purpose of study was the development and testing of a numerical simulation method for the cycloidal rotor and study aerodynamic and energy characteristics of the rotor in the hovering mode and under the influence of the oncoming flow. The aerodynamic and energy characteristics of the cycloidal rotor, rotating at a speed of 1000 rpm with incoming flow on it with velocities of 20-80 km/h, were calculated. The calculation results showed a directly proportional increase of thrust with an increase of the incoming on the rotor flow velocity, but the power consumed by the rotor was also increased. Increase of the incoming flow velocity leads to the proportional increasing of the lift coefficient and the coefficient of drag. Up to a speed of 80 km/h, an increase in thrust and power is observed; at higher speeds, there is a predominance of nonstationary effects and difficulties in estimating the aerodynamic characteristics of the rotor. In the future, it is planned to consider the 3D formulation of the problem combined with possibility of the flow coming from other sides.

On Numerical Simulation of Fuel Mixed With Steam or Air to Investigate Soot and Other Emissions

2015 ◽  
Author(s):  
Ajit Patki ◽  
Xianchang Li ◽  
Daniel Chen ◽  
Helen Lou ◽  
Vijaya Damodara
Keyword(s):  
Combustion Efficiency ◽  
Combustion Mechanism ◽  
Fuel Type ◽  
Ansys Fluent ◽  
Pm 2.5 ◽  
Combustion Gases ◽  
Numerical Studies ◽  
Baseline Case ◽  
Substantial Risk ◽  
Pdf Model

Soot emissions (PM 2.5) as well as CO and NOx from industrial flares and other industrial processes or sources pose a substantial risk to human being health and the environment, and now are subject to new and tougher EPA regulations. Flaring is used widely used in many industries to dispose unwanted combustion gases by burning them as a flame. However, flaring produces significant amount of particulate matter in the form of soot, along with other harmful gas emissions. Although many experimental and numerical studies have previously been done on flames burning in a controlled condition, relatively few studies have been conducted with fuel-steam mixture. In practice, air and steam are commonly used to assist the flaring processes — control the smoke and the combustion efficiency. This study aims to investigate soot, CO and NOx emissions of turbulent diffusion methane and propane flame mixed with air or superheated steam. To study such effect numerically, the computational fluid dynamics software ANSYS Fluent 14.5 is used with non-premixed probability density function (PDF) model. The laminar flamelet is generated with automated grid refinement. For the soot generation, the Moss-Brookes soot model with Lee sub-model is considered. The combustion mechanism is developed by the authors’ research group from the combined GRI and USC mechanisms. Two types of fuel, methane and propane, are used. The amount of super-heated steam varied from four percent to twenty percent (4%, 8 %, 12%, 16%, and 20%), and the behavior of the flame is analyzed. For the baseline case, the jet has a diameter of 50.8 mm or 2 inches, and the jet velocity is kept to 1.0 m/s. A co-flow air is supplied at a velocity of 0.2 m/s. The temperature distribution of methane and propane are compared with different contents of steam or air assists. The NOx, Soot and CO yields (kg/kg) varying with steam or air percentages are also presented. The results indicate that the soot yield is dependent on fuel type strongly and the percentage of steam or air affects the soot yield differently as the fuel type varies.

scholarly journals Combustion of Fuel Surrogates: An Application to Gas Turbine Engines

2021 ◽  
Author(s):  
Mansour Al Qubeissi ◽  
Nawar Al-Esawi ◽  
Hakan Serhad Soyhan
Keyword(s):  
Gas Turbine ◽  
Combustion Process ◽  
Chemical Mechanism ◽  
Cfd Modelling ◽  
Ansys Fluent ◽  
Turbine Engine ◽  
Fuel Blends ◽  
Combustion Simulation ◽  
Fuel Surrogate ◽  
Fuel Surrogates

The previously developed models for fuel droplet heating and evaporation processes, mainly the Discrete Multi Component Model (DMCM), and Multi-Dimensional Quasi-Discrete Model (MDQDM) are investigated for the aerodynamic combustion simulation. The models have been recently improved, and generalised for a broad range of bio-fossil fuel blends so that the application areas are broadened with increased accuracy. The main distinctive features of these models are that they consider the impacts of species thermal conductivities and diffusivities within the droplets to account for the temperature gradient, transient diffusion of species and recirculation. A formulation of fuel surrogates is made, using the recently introduced model, referred to as ‘’Complex Fuel Surrogate Model (CFSM)’’ and analysing their heating, evaporation, and combustion characteristics. The CFSM is aimed to reduce the full composition of fuel to a much smaller number of components based on their mass fractions, and to formulate fuel surrogates. Such approach has provided a proof of concept with the implementation of the developed model into a commercial CFD code ANSYS-Fluent. A case study is made for the CFD modelling of gas-turbine engine using kerosene fuel surrogate. The surrogate is proposed using the CFSM. The model is implemented into ANSYS-Fluent via a user-defined function to provide the first full simulation of the combustion process. Detailed chemical mechanism is also implemented into ANSYS Chemkin for the combustion study.

scholarly journals Numerical Analysis of the Combustion of Gases Generated during Biomass Carbonization

Entropy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 181
Author(s):  
Robert Zarzycki ◽  
Rafał Kobyłecki ◽  
Zbigniew Bis
Keyword(s):  
Combustion Process ◽  
Biomass Feedstock ◽  
Safe Operation ◽  
Separate Paper ◽  
Biomass Processing ◽  
Afterburning Chamber ◽  
Combustion Of Gases ◽  
Calculation Results ◽  
Design And Manufacture ◽  
Operational Data

The paper deals with the analysis of the combustion of volatiles evolved during thermolysis (thermal treatment) of biomass feedstock. The process is tailored to produce charcoal (biochar), heat and electricity and the whole system consists of a carbonizer, afterburning chamber and steam recovery boiler. In order to maintain safe operation of the carbonizer the process temperature has to be maintained at an acceptable level and thus the majority of gases evolved during biomass processing have to be combusted outside in the afterburning chamber. In this paper the combustion of those gases in a specially-designed combustion chamber was investigated numerically. The calculation results indicated that the production of the biochar has to be carried out with tight integration and management of the heat produced from the combustion of the volatiles and the emission of CO and methane may be maintained at a low level by optimization of the combustion process. The most promising effects were achieved in cases C4 and C5 where the gas was fed tangentially into the afterburning chamber. The calculation results were then used for the design and manufacture of a pilot reactor—from which the parameters and operational data will be presented and discussed in a separate paper.

scholarly journals CFD analysis of the ventilation heating system

2019 ◽  
Vol 20 (7) ◽  
pp. 708
Author(s):  
Miroslav Rimár ◽  
Andrii Kulikov ◽  
Marcel Fedak ◽  
Milan Abraham
Keyword(s):  
Heat Balance ◽  
Cfd Simulation ◽  
Heating System ◽  
Cfd Analysis ◽  
Ansys Fluent ◽  
Closed Area ◽  
Building Ventilation ◽  
Passive Houses ◽  
Air Circulation ◽  
The Heat Balance

Air conditioning is a significant part of the contemporary life. A lot of the medical papers confirmed the influence of the thermal comfort to the operability. The aim of the article is to understand the system of the building ventilation with the HRV unit. For this purpose, the CFD simulation model was elaborated. The ANSYS Fluent allows to calculate the heat balance of the room with secondary thermal gains like computers, monitors and humans. The results of the simulation approved that in the modern thermal passive houses heat balance calculations should take into account secondary thermal gains from the installed equipment. Also the air circulation in the closed area and the influence of the different barriers installed in the laboratory were investigated.

Numerical Calculation of the Force Coefficient for Cylindrical Shape Smokestack Covered with Corrugated Iron

2016 ◽  
Vol 821 ◽  
pp. 79-84
Author(s):  
Vladimira Michalcova ◽  
Lenka Lausova
Keyword(s):  
Numerical Calculation ◽  
Circular Cylinder ◽  
Numerical Modelling ◽  
Aerodynamic Drag ◽  
Cylindrical Shape ◽  
Force Coefficient ◽  
Ansys Fluent ◽  
Aerodynamic Drag Coefficient ◽  
Aerodynamic Roughness ◽  
Des Model

The article deals with the influence of a shape of the smokestacks casing on the final load from wind effects. It describes possibilities of defining an equivalent aerodynamic roughness and aerodynamic drag coefficient for numerical modelling of the flow around a circular cylinder. The aim is to determine the force coefficient for a smokestack of a cylindrical shape, which is sheeted with corrugated sheet metal. The flow around a smokestack is solved in software Ansys Fluent using the DES model.

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