Simulation of Airflow in the Engine Compartment of a Light Aircraft

2013 ◽  
Vol 284-287 ◽  
pp. 930-936
Author(s):  
Hsu Jeng Liu ◽  
Chih Chun Su ◽  
Sheng Liang Huang
Keyword(s):  
Guide Vane ◽  
Prototype Model ◽  
Engine Compartment ◽  
Air Inlet ◽  
Engine Cylinder ◽  
Improvement Method ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Very High ◽  
Economic Improvement

This paper applies the software of Computational Fluid Dynamics (CFD)-FLUENT to analyze the flow field in the engine compartment of a light aircraft. The simulation results of the prototype model indicates that the airflow rapidly flows to the back of the engine compartment along the inside cowling after entering the engine compartment, rather than to the engine cylinder which will result in a very high cylinder temperature. Hence, this paper designs the air inlet, air duct, guide vane, and air outlet to improve the airflow in the engine compartment according to the drawbacks of the prototype model. The results show that the air duct and the guide vane help lead the airflow to the cylinder, and the air outlet effectively reduces the pressure in the engine compartment so that the airflow accelerates through the engine compartment, which is considered a feasible and economic improvement method in terms of the production cost.

A STUDY ON THE ENGINE COMPARTMENT AIRFLOW OF A LIGHT AIRCRAFT USING COMPUTATIONAL FLUID DYNAMICS

2013 ◽  
Vol 37 (3) ◽  
pp. 641-653
Author(s):  
Hsu-jeng Liu ◽  
Chih-chun Su ◽  
Sheng-liang Huang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Guide Vane ◽  
Flow Characteristics ◽  
Prototype Model ◽  
Engine Compartment ◽  
Flow Conditions ◽  
Airflow Velocity ◽  
Air Inlet

This study applies FLUENT to simulate and analyze the flow characteristics in the engine compartment of a light aircraft. The air inlet, air duct, guide vane, and air outlet are designed to improve the flow conditions according to the drawbacks of the prototype model. The results show that the air duct and guide vane lead the airflow to the certain position of cylinders, and the air outlet reduces the pressure in the engine compartment. Moreover, combining these designs significantly increases the overall airflow velocity in the engine compartment.

Development of a Simulation Model to Investigate Tool Wear in Ti-6Al-4V Alloy Machining

2011 ◽  
Vol 223 ◽  
pp. 535-544 ◽  
Author(s):  
Volker Schulze ◽  
Frederik Zanger
Keyword(s):  
Tool Wear ◽  
High Strength ◽  
State Variables ◽  
Wear Model ◽  
Fem Model ◽  
Load Variations ◽  
Wear Rates ◽  
Simulation Results ◽  
Mechanical Machining ◽  
Very High

Titanium alloys like Ti‑6Al‑4V have a low density, a very high strength and are highly resistant to corrosion. However, the positive qualities in combination with the low heat conductivity have disadvantageous effects on mechanical machining and on cutting in particular. Ti‑6Al‑4V forms segmented chips for the whole range of cutting velocities which influences tool wear. Thus, optimization of the manufacturing process is difficult. To obtain this goal the chip segmentation process and the tool wear are studied numerically in this article. Therefore, a FEM model was developed which calculates the wear rates depending on state variables from the cutting simulation, using an empirical tool wear model. The segmentation leads to mechanical and thermal load variations, which are taken into consideration during the tool wear simulations. In order to evaluate the simulation results, they are compared with experimentally obtained results for different process parameters.

How Computational Grid Refinement in Three Dimensions Affects CFD-DEM Results for Psuedo-2D Fluidized Gas-Solid Beds

2017 ◽  
Author(s):  
Annette Volk ◽  
Urmila Ghia
Keyword(s):  
Three Dimensional ◽  
Computational Grid ◽  
Three Dimensions ◽  
Computational Grids ◽  
Grid Refinement ◽  
2D Simulation ◽  
Computational Fluid Dynamics Cfd ◽  
Bed Thickness ◽  
Simulation Results ◽  
Accuracy Of Results

Computational Fluid Dynamics (CFD)-Discrete Element Method (DEM) simulations are designed to model a pseudo-two-dimensional fluidized bed. Bed behavior and accuracy of results are shown to change as the simulations are conducted on increasingly refined computational grids. Trends of the results with grid refinement are reported for both three-dimensional, uniform refinement, and for grid refinement in only the direction of bed thickness. Pseudo-2D simulation results are examined against previously published experimental data to assess relative accuracy compared to fully 3D simulation results. Two drag laws are employed in the simulations, resulting in different trends of results with computational grid refinement. From these results, we present suggestions for accurate model design.

Numerical Simulation of the Thermodynamic Process of the Molten Salt Furnace

2012 ◽  
Author(s):  
Lian Ning ◽  
Chenn Q. Zhou ◽  
Jiemin Zhou
Keyword(s):  
Molten Salt ◽  
Gas Flow ◽  
Radiative Heat ◽  
Guide Vane ◽  
Furnace Chamber ◽  
Air Flow Rate ◽  
Thermodynamic Process ◽  
Volumetric Concentration ◽  
Flow Temperature ◽  
Simulation Results

In this paper, a numerical model of the thermodynamic process was developed, by using CFD (software) technique and considering the gas flow, the diffused combustion and the radiative heat transfer in the molten salt furnace. This model aims to optimize the operating parameters. Simulation results demonstrate that the performances of the salt furnace can be improved by optimization. The temperatures along the fire wall circumference are quite even, and the deviant combustion phenomenon is not observed. A back-flow formed in the upper part of the furnace chamber enhances the circulation and the mixing of the gas, helping to effectively stabilize the combustion in the furnace. The behaviors of CO, CO2, NOx and H2O are presented in terms of the gas flow, temperature distribution and volumetric concentration distribution. The furnace with the constant air flow rate of 15500Nm3/h and the angle of guide vane at 48∼50 ° can increase the combustion effectiveness.

Mathematical model of the artificial muscle with two actuators

2020 ◽  
pp. 095440622094156
Author(s):  
Ljubinko B Kevac ◽  
Mirjana M Filipovic ◽  
Ana M Djuric
Keyword(s):  
Mathematical Model ◽  
Control Structure ◽  
Artificial Muscle ◽  
Parallel Robot ◽  
Simulation Results ◽  
Proportional Derivative Controller ◽  
Definition Of ◽  
The Mathematical Model ◽  
The Given ◽  
Very High

Characteristic construction of cable-suspended parallel robot of artificial muscle, which presents an artificial forearm, is analyzed and synthesized. Novel results were achieved and presented. Results presented in this paper were initially driven to recognize and mathematically define undefined geometric relations of the artificial forearm since it was found that they strongly affect the dynamic response of this system. It gets more complicated when one has more complex system, which uses more artificial muscle subsystems, since these subsystems couple and system becomes more unstable. Unmodeled or insufficiently modeled dynamics can strongly affect the system’s instability. Because of that, the construction of this system and its new mathematical model are defined and presented in this paper. Generally, it can be said that the analysis of geometry of selected mechanism is the first step and very important step to establish the structural stability of these systems. This system is driven with two actuators, which need to work in a coordinated fashion. The aim of this paper is to show the importance of the geometry of this solution, which then strongly affects the system’s kinematics and dynamics. To determine the complexity of this system, it was presumed that system has rigid cables. Idea is to show the importance of good defined geometry of the system, which gives good basis for the definition of mathematical model of the system. Novel program package AMCO, artificial muscle contribution, was defined for the validation of the mathematical model of the system and for choice of its parameters. Sensitivity of the system to certain parameters is very high and hence analysis of this system needs to be done with a lot of caution. Some parameters are very influential on the possible implementation of the given task of the system. Only after choosing the parameters and checking the system through certain simulation results, control structure can be defined. In this paper, proportional–derivative controller was chosen.

scholarly journals Analysis of Cyclist’s Drag on the Aero Position Using Numerical Simulations and Analytical Procedures: A Case Study

2020 ◽  
Vol 17 (10) ◽  
pp. 3430 ◽  
Author(s):  
Pedro Forte ◽  
Daniel A. Marinho ◽  
Pantelis T. Nikolaidis ◽  
Beat Knechtle ◽  
Tiago M. Barbosa ◽  
...  
Keyword(s):  
Linear Regression ◽  
Numerical Simulations ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Paired Samples ◽  
Computational Fluid Dynamics Cfd ◽  
Analytical Procedures ◽  
Previous Training ◽  
Very High

Background: Resistance acting on a cyclist is a major concern among the cycling fraternity. Most of the testing methods require previous training or expensive equipment and time-consuming set-ups. By contrast, analytical procedures are more affordable and numerical simulations are perfect for manipulating and controlling inputs. The aim of this case study was to compare the drag of a cyclist in the aero position as measured using numerical simulation and analytical procedures. Methods: An elite male cyclist (65 kg in mass and 1.72 m in height) volunteered to take part in this research. The cyclist was wearing his competition gear, helmet and bicycle. A three-dimensional model of the bicycle and cyclist in the aero position was obtained to run the numerical simulations. Computational fluid dynamics (CFD) and a set of analytical procedures were carried out to assess drag, frontal area and drag coefficient, between 1 m/s and 22 m/s, with increments of 1 m/s. The t-test paired samples and linear regression were selected to compare, correlate and assess the methods agreement. Results: No significant differences (t = 2.826; p = 0.275) between CFD and analytical procedures were found. The linear regression showed a very high adjustment for drag (R2 = 0.995; p < 0.001). However, the drag values obtained by the analytical procedures seemed to be overestimated, even though without effect (d = 0.11). Conclusions: These findings suggest that drag might be assessed using both a set of analytical procedures and CFD.

scholarly journals A Study on the Thermal Performance of Air-Type BIPVT Collectors Applied to Demonstration Building

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3120 ◽  
Author(s):  
Ji-Suk Yu ◽  
Jin-Hee Kim ◽  
Jun-Tae Kim
Keyword(s):  
Thermal Performance ◽  
Thermal Characteristics ◽  
Building Energy ◽  
Flow Path ◽  
Heating And Cooling ◽  
Building Integrated Photovoltaic ◽  
Opening Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Inlet Opening

Research on existing air-type PVT (photovoltaic/thermal) collectors has mainly focused on improving the efficiency of the collector itself and on using the energy produced by the collector in heating and cooling facilities and building energy. The first consideration in an air-type PVT system applied to a building facade is the collector arrangement and the flow path considering the collector performance. It is necessary to design the flow inside the air-type BIPVT (building integrated photovoltaic/thermal) collector so that it runs smoothly so as not to cause a dead space and a pressure drop inside the collector, which deteriorate the thermal performance. This study analyzed the thermal characteristics of an air-type BIPVT collector applied to a demonstration building (educational buildings) according to the air flow path and inlet opening ratio. For this purpose, the uniformity of the airflow in the collector was compared through the NX computational fluid dynamics (CFD) program, and the acquired thermal calories and thermal efficiency of the BIPVT collector were compared and analyzed. Based on the simulation results, the temperature and thermal characteristics of the BIPVT collector were compared.

Optimal Hardware Placement in a Minitower Computer Enclosure System

2011 ◽  
Author(s):  
M. Alfaro Cano ◽  
A. Hernandez-Guerrero ◽  
C. Rubio Arana ◽  
Aristotel Popescu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Operating Temperature ◽  
Optimal Placement ◽  
Cfd Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
The Relationship ◽  
Key Questions

One of the requirements for existing personal computers, PCs, is that the hardware inside must maintain an operating temperature as low as possible. One way to achieve that is to place the hardware components at locations with enough airflow around it. However, the relationship between the airflow and temperature of the components is unknown before they are placed at specific locations inside a PC. In this work a Computational Fluid Dynamics (CFD) analysis is coupled to a Design of Experiment (DOE) methodology to answer typical minitower key questions: a) how do the possible positions of hardware components affect their temperature?, and b) is it possible to get an optimal placement for these hardware components using the data collected by the CFD simulation results? The DOE methodology is used to optimize the analysis for a very large number of possible configurations. The results help in identifying where the efforts need to be placed in order to optimize the positioning of the hardware components for similar configurations at the designing stage. Somehow the results show that general conclusions could be drawn, but that there are not specific rules that could be applied to every configuration.

Water Hammer in a Pumping Main and its Prevention

1951 ◽  
Vol 165 (1) ◽  
pp. 43-52 ◽  
Author(s):  
A. M. Binnie ◽  
D. G. Thackrah
Keyword(s):  
Theoretical Calculations ◽  
Pressure Fluctuations ◽  
Maximum Pressure ◽  
Relief Valve ◽  
Inlet Valve ◽  
Air Inlet ◽  
Pipe Line ◽  
Usual Theory ◽  
Set Up ◽  
Very High

An earlier investigation has been continued on the protection of a rising water main against the consequences of a sudden interruption in the supply. In place of the air bottle previously tried, an automatic air-inlet valve was placed at the lower end of the pipe-line. Experiments on a laboratory scale showed that the cushion of air thus introduced brought the returning water column to rest without sound or shock. Theoretical calculations of maximum pressure and of air drawn in were verified. The lift of the pipe-line being small compared with its length, it was found that, over the range of velocity usually employed, the maximum pressure set up by the returning column diminished as the initial velocity of the interrupted supply was increased. With no protective device in use, a series of violent impacts took place owing to the column striking and rebounding from the closed valve at the lower end of the pipe-line. An electronic gauge, having a very high natural frequency, was used to measure the magnitude and duration of the shock pressures. Its indications were generally in accord with an analysis based on the usual theory of pressure waves, but the maximum pressures actually recorded somewhat exceeded the theoretical estimates, owing to the existence of additional pressure fluctuations caused by reflections from bends, sockets, and other discontinuities in the pipe-line. The insertion of a spring-loaded relief valve only slightly reduced the shock pressures.

Gas Liquid Vane Separators in High Pressure Applications

2010 ◽  
Author(s):  
Dani Fadda ◽  
David Barker
Keyword(s):  
Separation Efficiency ◽  
Pressure Vessels ◽  
Cfd Modeling ◽  
Test Results ◽  
Capacity Curves ◽  
Liquid Handling ◽  
Wide Range ◽  
Computational Fluid Dynamics Cfd ◽  
Very High ◽  
High Separation

Vane separators are inertial devices used to remove entrained liquids from gas. They are utilized in pressure vessels operating at a wide range of temperatures and pressures. Computational Fluid Dynamics (CFD) modeling and sizing calculations are used to evaluate the loading to a vane separator and determine the maximum overall gas and liquid handling capacity of the pressure vessel. Test results, performed at operating pressures up to 133 bar (1931 psia) using live natural gas illustrate that, when sized correctly based on the vane’s capacity curves and CFD modeling, vane separators continue to have high separation efficiency at very high operating pressures.

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