Experimental investigation of the air flow in a simplified underhood environment

2021 ◽  
pp. 095440702110597
Author(s):  
Randi Franzke ◽  
Simone Sebben ◽  
Emil Willeson
Keyword(s):  
Flow Field ◽  
Laser Doppler Anemometry ◽  
Fluid Dynamic ◽  
Air Flow ◽  
Measurement Data ◽  
Quality Measurement ◽  
Flow Distribution ◽  
Lateral Position ◽  
Reference Case ◽  
Lateral Direction

In this paper, a simplified underhood environment is proposed to investigate the air flow distribution in a vehicle-like set-up and provide high quality measurement data that can be used for the validation of Computational Fluid Dynamic methods. The rig can be equipped with two types of front openings representative for electrified vehicles. Furthermore, it is possible to install differently shaped blockages downstream of the fan to imitate large underhood components. The distance between the blockages and the fan can be varied in longitudinal and lateral direction. The measurements are performed with Laser Doppler Anemometry at a fixed distance downstream of the fan. The results show that the lack of an upper grille opening in the configuration for a battery electric vehicle has a notable impact on the flow field in the reference case without any downstream blockage. However, the differences in the flow field between the two front designs become less when a downstream obstruction is present. The longitudinal and lateral position of the blockages have a minor impact on the flow field compared to the shape of the obstacle itself.

Blade Fault Recognition Based on Signal Processing and Adaptive Fluid Dynamic Modelling

1997 ◽  
Author(s):  
A. Stamatis ◽  
N. Aretakis ◽  
K. Mathioudakis
Keyword(s):  
Flow Field ◽  
Fluid Dynamic ◽  
Measurement Data ◽  
Dynamic Modelling ◽  
Physical Modelling ◽  
Diagnostic Procedures ◽  
Measured Quantity ◽  
Test Cases ◽  
Actual Measurement ◽  
Fault Recognition

An approach for identification of faults in blades of a gas turbine, based on physical modelling is presented. A measured quantity is used as an input and the deformed blading configuration is produced as an output. This is achieved without using any kind of “signature”, as is customary in diagnostic procedures for this kind of faults. A fluid dynamic model is used in a manner similar to what is known as “inverse design methods”: the solid boundaries which produce a certain flow field are calculated by prescribing this flow field. In the present case a signal, corresponding to the pressure variation on the blade-to-blade plane, is measured. The blade cascade geometry that has produced this signal is then produced by the method. In the paper the method is described and applications to test cases are presented. The test cases include theoretically produced faults as well as experimental cases, where actual measurement data are shown to produce the geometrical deformations which existed in the test engine.

Numerical Simulation Applied to Study the Effects of Fractal Tree-Liked Network Channel Designs on PEMFC Performance

2012 ◽  
Vol 488-489 ◽  
pp. 1219-1223 ◽  
Author(s):  
Shan Jen Cheng ◽  
Jr Ming Miao ◽  
Chang Hsien Tai
Keyword(s):  
Fuel Cell ◽  
Pressure Drop ◽  
Flow Field ◽  
Fluid Dynamic ◽  
Flow Distribution ◽  
Flow Channel ◽  
Proton Exchange ◽  
Channel Network ◽  
Computational Fluid Dynamic Analysis ◽  
Network Channel

The effect of pressure drop and the flow-field of inhomogeneous transport of reactions gas are two important issues for bipolar flow channel design in proton exchange membrane fuel cell (PEMFC). A novel design through the imitation of biological development of the topology distribution of fractal tree-liked network channel is the main topic of this research. The effects of different Reynolds numbers and stoichiometric mass flow rate of reaction gas on the flow field distribution of tree-like channels were investigated by three-dimensional computational fluid dynamic analysis. According to numerical simulations, the fractal tree-liked network channel would have an excellent performance on the uniformity of multi-branching flow distribution and lower pressure drop along channels. The new type of fractal tree-liked bionic flow channel network design will be applied to assist in the experimental reference for improving the performance of fuel cell stack system in PEMFC for future.

Blade Fault Recognition Based on Signal Processing and Adaptive Fluid Dynamic Modeling

1998 ◽  
Vol 120 (3) ◽  
pp. 543-549 ◽  
Author(s):  
A. Stamatis ◽  
N. Aretakis ◽  
K. Mathioudakis
Keyword(s):  
Flow Field ◽  
Fluid Dynamic ◽  
Measurement Data ◽  
Physical Modelling ◽  
Diagnostic Procedures ◽  
Measured Quantity ◽  
Test Cases ◽  
Actual Measurement ◽  
Fault Recognition ◽  
Test Engine

An approach for identification of faults in blades of a gas turbine, based on physical modelling, is presented. A measured quantity is used as an input, and the deformed blading configuration is produced as an output. This is achieved without using any kind of “signature,” as is customary in diagnostic procedures for this kind of faults. A fluid dynamic model is used in a manner similar to what is known as “inverse design methods”: the solid boundaries that produce a certain flow field are calculated by prescribing this flow field. In the present case, a signal, corresponding to the pressure variation on the blade-to-blade plane, is measured. The blade cascade geometry that has produced this signal is then produced by the method. In the paper, the method is described, and applications to test cases are presented. The test cases include theoretically produced faults as well as experimental cases where actual measurement data are shown to produce the geometrical deformations that existed in the test engine.

A Study of Inlet Flow Distortion Effects on Automotive Catalytic Converters

1991 ◽  
Vol 113 (3) ◽  
pp. 419-426 ◽  
Author(s):  
G. Bella ◽  
V. Rocco ◽  
M. Maggiore
Keyword(s):  
Flow Field ◽  
Flow Rate ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Catalytic Converters ◽  
Flow Distortion ◽  
Local Flow ◽  
Positive Effects ◽  
Local Boundary Condition

This paper will focus on the influence exerted by a nonuniform flow distribution at the inlet of oxidizers to catalytic converters on conversion efficiency evaluated channel by channel. To this aim the flow inside the whole domain, constituted by the exhaust manifold and an elliptic-cross-sectional pipe connecting it with the converter shell, is simulated by means of a three-dimensional fluid-dynamic viscous model. In this way, after assigning typical converter size and geometry (i.e., elliptic) the gas flow rate distribution can be described at its inlet surface, also varying the total mass flow rate. After calculating the flow field at converter inlet by means of a three-dimensional model, evaluation is possible of local flow distortion in comparison with the ideal conditions of constant velocity of the gas entering the honeycomb converter channels. The abovementioned distorted flow field is then assigned as a local boundary condition for another model, developed by the authors, able to describe, through a one-dimensional fluid-dynamic approach, the reacting flow into the converter channels. It was also shown that, due to this flow distortion, honeycomb converters are not uniformly exploited in terms of pollutants of different quantities to be converted in each channel (i.e., a nonuniform exploitation of all the metals coating the ceramic monolith). Finally, the positive effects determined by a diffuser upstream of the converter on flow distribution are analyzed.

Numerical and Experimental Analysis of the Intake Flow in a High Performance Four-Stroke Motorcycle Engine: Influence of the Two-Equation Turbulence Models

2007 ◽  
Vol 129 (4) ◽  
pp. 1095-1105 ◽  
Author(s):  
Angelo Algieri ◽  
Sergio Bova ◽  
Carmine De Bartolo ◽  
Alessandra Nigro
Keyword(s):  
Flow Field ◽  
Combustion Chamber ◽  
High Performance ◽  
Laser Doppler Anemometry ◽  
Fluid Dynamic ◽  
Turbulence Models ◽  
Mean Flow ◽  
Intake System ◽  
Cylinder Flow ◽  
Motorcycle Engine

An experimental and numerical analysis of the intake system of a production high performance four-stroke motorcycle engine was carried out. The aim of the work was to characterize the fluid dynamic behavior of the engine during the intake phase and to evaluate the capability of the most commonly used two-equation turbulence models to reproduce the in-cylinder flow field for a very complex engine head. Pressure and mass flow rates were measured on a steady-flow rig. Furthermore, velocity measurements were obtained within the combustion chamber using laser Doppler anemometry (LDA). The experimental data were compared to the numerical results using four two-equation turbulence models (standard k-ε, realizable k-ε, Wilcox k-ω, and SST k-ω models). All the investigated turbulence models well predicted the global performances of the intake system and the mean flow structure inside the cylinder. Some differences between measurements and computations were found close to the cylinder head while an improving agreement was evident moving away from the engine head. Furthermore, the Wilcox k-ω model permitted the flow field inside the combustion chamber of the engine to be reproduced and the overall angular momentum of the flux with respect to the cylinder axis to be quantified more properly.

Computer-Aided Design of a Cleanroom Ceiling Plenum System with a Limited Space for HVAC Equipment

1999 ◽  
Vol 42 (6) ◽  
pp. 34-39 ◽  
Author(s):  
Ting-Kwo Lei ◽  
Andrew Manning ◽  
Felix Kersting
Keyword(s):  
Flow Field ◽  
Computational Fluid Dynamic ◽  
Computer Aided Design ◽  
Fluid Dynamic ◽  
Flow Distribution ◽  
Velocity Fields ◽  
Computer Aided ◽  
Distribution Uniformity ◽  
Aided Design ◽  
Number Of Cells

Acommercial Computational Fluid Dynamic (CFD) software program was used to analyze the flow field inside a cleanroom ceiling plenum. The design required restricted space for the HVAC equipment. The effect of the number of cells used in the computational model on the simulation output was investigated. Pressure and velocity fields were examined. A comparison of flow distribution uniformity between a reference ceiling plenum system and a ceiling plenum system containing more ducted air supplies was made. An analysis of the effect of diffusion plates was conducted.

Computational Fluid Dynamics Analysis for Flow Field of Radiator Air Intake in the Powertrain Compartment

2013 ◽  
Vol 464 ◽  
pp. 171-175
Author(s):  
Lin Lin Song ◽  
Wei Zheng Zhang ◽  
Yuan Fu Cao ◽  
Ya Lei Zeng
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Air Flow ◽  
Flow Distribution ◽  
Heat Transfer Analysis ◽  
Wind Speeds ◽  
Computational Fluid Dynamics Analysis ◽  
Cooling Air Flow ◽  
Cooling Air

A computational fluid dynamics (CFD) model of tank powertrain compartment was constructed for cooling air flow and heat transfer analysis. The key points temperatures of the powertrain compartment were tested, and the numerical values have a good agreement with the measurement datas. Detailed cooling air flow field distributing characteristic through radiators in the powertrain compartment were obtained through numerical method, with different fan speeds and ambient wind speeds. These results can provide the basis for the choice of the fan speed on specific condition and the air flow distribution of the radiator.

Numerical Simulation of Flow Filed in ESP Outlet with Moving Electrode Type

2012 ◽  
Vol 485 ◽  
pp. 27-30
Author(s):  
Man Yin Hu ◽  
Yu Chao Liang ◽  
Kai Che ◽  
Guang Han ◽  
Xiang Chen
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Flow Velocity ◽  
Geometric Model ◽  
Air Flow ◽  
Flow Distribution ◽  
Simple Algorithm ◽  
Equation Model ◽  
Opening Ratio ◽  
Air Flow Velocity

The numerical simulation of 2-D flow filed in ESP with Moving Electrode Type was carried out, in which a 2-equation model was adopted to simulate the flow field and the computation based on the SIMPLE algorithm and the geometric model was meshed with GAMBIT. The numerical simulation of flow field with FLUENT came to the conclusion that the air flow distribution in the electro static precipitator will change when the opening ratio of the electrodes and the air flow velocity in operation have changed, so the result of numerical simulation was reasonable for the design and operation of the ESP with Moving Electrode Type.

Experimental and numerical analysis of an improved melt-blowing slot-die

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 612-621 ◽  
Author(s):  
Yudong Wang ◽  
Changchun Ji ◽  
Jianping Zhou
Keyword(s):  
Flow Field ◽  
Air Flow ◽  
Measurement Data ◽  
Central Area ◽  
Melt Blowing ◽  
Maximum Value ◽  
Die Surface ◽  
Slot Die ◽  
Two Dimensional Flow ◽  
The Common

AbstractIn order to reduce the melt-blowing fiber diameter, an improved slot die with internal stabilizers was designed. The air-flow field of the improved die was measured by a hot wire anemometer. Furthermore, utilizing computational fluid dynamics software, the air flow field from the improved slot die was studied and the work was validated with the laboratory measurement data. The experimental results and numerical simulation data indicate below the die surface, the internal stabilizers play an important role in the velocity distribution of the flow field. Firstly, the improved slot die can increase the velocity and the temperature near the centerline of the flow field and reduce the maximum value of turbulent kinetic energy, compared to the common die. Secondly, the end face of the slot hole has a certain influence on the surrounding flow field and the central area exhibits two-dimensional flow field distribution.

Experimental Investigation of the Turbulent Flow Field of Vaporizing Diesel-Sprays

2002 ◽  
Author(s):  
Michael Staudt ◽  
Ulrich Meingast ◽  
Ulrich Renz
Keyword(s):  
Flow Field ◽  
Gas Flow ◽  
Elevated Temperatures ◽  
Laser Doppler Anemometry ◽  
Air Flow ◽  
Injection System ◽  
Penetration Length ◽  
Fuel Droplets ◽  
Fuel Jet ◽  
Dimensional Measurements

In this work investigations of the flow-field inside and around a heated, vaporizing diesel-fuel-jet are presented. The experiments are carried out in a high-pressure-chamber at elevated temperatures using a commercial Bosch-Common-Rail Diesel-injection system. The pressure and temperature inside the chamber are chosen according to the conditions in a real engine cylinder after compression. Droplet diameters and velocities inside the fuel jet are measured by means of Phase-Doppler-Anemometry (PDA). In order to obtain the velocities of the gas phase very close to the free penetrating fuel jet by Laser-Doppler-Anemometry (LDA), the air inside the chamber is seeded with Titan-Dioxide (TiO2)-particles. Turbulence values like RMS and length scales are derived from these measurements. In addition to these spatially limited measurements the global flow-field around the penetrating fuel-jet is observed by two-dimensional measurements with Particle-Image-Velocimetry (PIV). From the nozzle exit up to 2/3 of the whole penetration length an air flow perpendicular to the spray axis can be detected. This air-flow into the spray provides the heat transfer and vaporization of the fuel-droplets. The fuel jet contains a high droplet concentration which leads to high intensities in the resulting PIV-images from which discrete spray contours can be calculated. By means of the gas-flow velocity components at this contour the total mass of the absorbed air is calculated. This mass is compared at three injection pressures: 80, 100 and 135 MPa. Further experiments concentrate on a spray impinging straight onto a flat wall. The wall jet leads to additional contributions of air absorption into regions with high droplet concentrations.

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