Review: CFD Applications in the Automotive Industry

1996 ◽  
Vol 118 (4) ◽  
pp. 647-653 ◽  
Author(s):  
M. N. Dhaubhadel
Keyword(s):  
Automotive Industry ◽  
Cycle Time ◽  
Computer Hardware ◽  
System Level ◽  
Design Environment ◽  
Component Level ◽  
Automotive Design ◽  
Design Changes ◽  
Wide Range ◽  
Cfd Applications

A general review of Computational Fluid Dynamics (CFD) applications in the automotive industry is presented. CFD has come a long way in influencing the design of automotive components due to continuing advances in computer hardware and software as well as advances in the numerical techniques to solve the equations of fluid flow. The automotive industry’s interest in CFD applications stems from its ability to improve automotive design and to reduce product cost and cycle time. We are able to utilize CFD more and more in day-to-day automotive design, and we can expect better conditions for CFD applications in the coming years. CFD applications in the automotive industry are as numerous as are the codes available for the purpose. Applications range from system level (e.g., exterior aerodynamics) to component level (e.g., disk brake cooling). The physics involved cover a wide range of flow regimes (i.e., incompressible, compressible, laminar, turbulent, unsteady, steady, subsonic and transonic flows). Most of the applications fall in the incompressible range and most are turbulent flows. Although most of the flows encountered are unsteady in nature, a majority of them can be approximated as steady cases. The challenge today is to be able to simulate accurately some very complex thermo-fluids phenomena, and to be able to get CFD results fast, in order to effectively apply them in the “dynamic” design environment of frequent design changes. The key is to utilize CFD in the early design phases so that design changes and fix-ups later are minimized. Proper use of CFD early, helps to significantly reduce prototyping needs and consequently, reduce cost and cycle time.

scholarly journals A Methodology for the Experimental Validation of an Aircraft ECS Digital Twin Targeting System Level Diagnostics

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Shafayat Hasan Chowdhury ◽  
Fakhre Ali ◽  
Ian K. Jennions
Keyword(s):  
Environmental Control ◽  
System Level ◽  
Aviation Industry ◽  
Diagnostic Process ◽  
Health State ◽  
Air Conditioner ◽  
Component Level ◽  
Digital Twin ◽  
Wide Range ◽  
Thermodynamic Performance

The Environmental Control System (ECS) of an aircraft is responsible for regulating and conditioning the airflow into the cockpit, cabin and avionics bay. The ECS is composed of several complex sub-systems and components that are reported as key unscheduled maintenance drivers for legacy aircraft by aircraft operators. Furthermore, the incorporated temperature and flow control valves in these sub-systems have the capability to mask potential faults at the component level, making the diagnostic process very challenging. To overcome this challenge, the aviation industry is currently proactively exploring the predictive maintenance approach that allows real-time monitoring of the key systems, sub-systems and components. In the context of the ECS, this necessitates the requirement to equip the system with appropriate condition monitoring capabilities. To do this, the performance characteristics of the ECS at sub-system and component level needs to be well understood under a wide-range of aircraft operating scenarios. Existing literature provides component level and system level analyses of the ECS. However, it lacks an experimentally verified and validated ECS sub-system and component level simulation tool (ECS Digital Twin), capable of simulating the thermodynamic performance and component health state parameters under wide-ranging aircraft operational scenarios. The ECS Digital Twin (DT) developed by the Cranfield University IVHM Centre offers the capability to simulate healthy and faulty cases of the Passenger Air Conditioner (PACK). This paper proposes a methodology for full-scale experimental Verification & Validation (V&V) of the developed ECS DT, to enable component level simulation, and enabling accurate diagnostics, of the civil aircraft ECS. The paper reports on progress to date in this project.

Management of Sampling Uncertainty Using Conservative Estimate of Probability in Bayesian Network

2017 ◽  
Author(s):  
Sangjune Bae ◽  
Nam H. Kim ◽  
Seung-gyo Jang
Keyword(s):  
Sensitivity Analysis ◽  
Bayesian Network ◽  
Global Sensitivity Analysis ◽  
Epistemic Uncertainty ◽  
Probability Of Failure ◽  
System Level ◽  
Conservative Estimate ◽  
Component Level ◽  
Global Sensitivity ◽  
Design Changes

Since the safety of a system is often assessed by the probability of failure, it is crucial to calculate the probability accurately in order to achieve the target safety. Despite such importance, calculating the precise probability is not a trivial task due to the inherent aleatory variability and epistemic uncertainty. Therefore the safety is assessed by a conservative estimate of the probability rather than using a single value of the probability. In general, there are two ways to achieve the target probability: Shifting the probability or reducing the uncertainty. In this paper, among various sources of epistemic uncertainty, the uncertainty quantification error from sampling is considered to calculate the conservative estimate of a system probability of failure. To quantify and shape the epistemic uncertainty, Bayesian network is utilized for constituting the relationship between the system probability and component probabilities, while global sensitivity analysis is employed to connect the variance in the probabilities in system level with that in the component level. Based on this, local sensitivity of the conservative estimate with respect to a design change in a component is derived and approximated for a simple numerical calculation using Bayesian network and global sensitivity analysis. This is to show how a design can meet the probabilistic criteria considering propagated uncertainty when the design changes.

A High-Speed Disk Rotor Rig Design for Tip Aerothermal Research

2020 ◽  
Author(s):  
S. Lu ◽  
Q. Zhang ◽  
L. He
Keyword(s):  
High Speed ◽  
Cfd Simulation ◽  
Optical Measurement ◽  
Design Concept ◽  
System Level ◽  
Tip Leakage Flow ◽  
Component Level ◽  
Tip Leakage ◽  
Rotor Design ◽  
Wide Range

Abstract The relative casing motion can greatly vary the Over-Tip-Leakage (OTL) flow structure and thermal performance. The existing tip experimental research facilities include stationary linear cascade, cascade rigs with low speed moving belt, or high-speed rotor rigs are either not capable of reproducing the high relative casing Mach number, or extremely expensive and still difficult for optical measurement. This paper presents a highspeed disk rotor design which can simulate the high casing relative speed. The unique feature of this rig design concept is that it enables full optical access of the tip surface under the engine-representative OTL flow condition. In this paper, the feasibility of the design concept is demonstrated and assessed by RANS CFD simulation, both in component level and whole rig system level. The design idea demonstrated in this paper can be useful for a wide range of tip leakage flow studies.

Dynamic Infrared System Level Fault Isolation

2003 ◽  
Author(s):  
John A. Naoum ◽  
Johan Rahardjo ◽  
Yitages Taffese ◽  
Marie Chagny ◽  
Jeff Birdsley ◽  
...  
Keyword(s):  
Fault Isolation ◽  
System Level ◽  
System Component ◽  
Component Level ◽  
Ir Imaging ◽  
Non Destructive

Abstract The use of Dynamic Infrared (IR) Imaging is presented as a novel, valuable and non-destructive approach for the analysis and isolation of failures at a system/component level.

Improved Roller Hemming System for High Volume Part Production

2011 ◽  
Vol 473 ◽  
pp. 168-175 ◽  
Author(s):  
Martin Zubeil ◽  
Karl Roll ◽  
Marion Merklein
Keyword(s):  
Strain Rate ◽  
Surface Quality ◽  
Automotive Industry ◽  
Dimensional Stability ◽  
Cycle Time ◽  
High Volume ◽  
Non Linear ◽  
Part Production

Roller hemming is usually applied for hang-on-parts such as hoods, doors or trunk-lids which all have complex non-linear geometries. The flange is often hemmed along both surfaces and edges which have 3D curvilinear shapes. Minimization of hemming defects and the requirement to improve cycle time of the roller hemming process are essential for roller hemmed hang-on-parts in the automotive industry. Different systems such as the driven roller hemming provide the possibility to increase the strain rate without loosing surface quality and dimensional stability. Investigating the influence of friction during roller hemming, results will give an understanding of the advantage for mentioned roller hemming systems.

Analysis and Reduction of the Waste in the Work Process Using Time Study Analysis: A Case Study

2014 ◽  
Vol 660 ◽  
pp. 971-975 ◽  
Author(s):  
Mohd Norzaim bin Che Ani ◽  
Siti Aisyah Binti Abdul Hamid
Keyword(s):  
Cycle Time ◽  
Lean Manufacturing ◽  
Value Added ◽  
Time Study ◽  
Study Approach ◽  
Root Cause ◽  
Wide Range ◽  
Unit Of Work ◽  
Time Required ◽  
The Impact

Time study is the process of observation which concerned with the determination of the amount of time required to perform a unit of work involves of internal, external and machine time elements. Originally, time study was first starting to be used in Europe since 1760s in manufacturing fields. It is the flexible technique in lean manufacturing and suitable for a wide range of situations. Time study approach that enable of reducing or minimizing ‘non-value added activities’ in the process cycle time which contribute to bottleneck time. The impact on improving process cycle time for organization that it was increasing the productivity and reduce cost. This project paper focusing on time study at selected processes with bottleneck time and identify the possible root cause which was contribute to high time required to perform a unit of work.

System Level Bench Test for Trailing Arm Strength Estimation

2006 ◽  
Author(s):  
Jaychandar Muthu ◽  
Kanak Soundrapandian ◽  
Jyoti Mukherjee
Keyword(s):  
Failure Mode ◽  
Real Life ◽  
Element Model ◽  
Suspension System ◽  
System Level ◽  
Bench Test ◽  
Component Level ◽  
Arm Strength ◽  
Bench Testing ◽  
Nonlinear Finite Element Model

For suspension components, bench testing for strength is mostly accomplished at component level. However, replicating loading and boundary conditions at the component level in order to simulate the suspension system environment may be difficult. Because of this, the component's bench test failure mode may not be similar to its real life failure mode in vehicle environment. A suspension system level bench test eliminates most of the discrepancies between simulated component level and real life vehicle level environments resulting in higher quality bench tests yielding realistic test results. Here, a suspension level bench test to estimate the strength of its trailing arm link is presented. A suspension system level nonlinear finite element model was built and analyzed using ABAQUS software. The strength loading was applied at the wheel end. The analysis results along with the hardware test correlations are presented. The reasons why a system level test is superior to a component level one are also highlighted.

Designing Soft Reactive Adhesives by Controlling Polymer Chemistry

MRS Bulletin ◽  
2003 ◽  
Vol 28 (6) ◽  
pp. 424-427 ◽  
Author(s):  
Agnès Aymonier ◽  
Eric Papon
Keyword(s):  
Automotive Industry ◽  
Ease Of Use ◽  
Large Strains ◽  
Structural Adhesives ◽  
Wide Range ◽  
Step Growth ◽  
Visible Irradiation ◽  
Step Growth Polymerization ◽  
Uv Visible ◽  
Activation Heat

AbstractSoft reactive adhesives (SRAs) are polymer-based materials (e.g., polyurethanes, polysiloxanes, polydienes) designed to be further vulcanized or slightly cross-linked through external activation (heat, moisture, oxygen, UV–visible irradiation, etc.), either at the time of their application or within a subsequent predefined period. They are used mainly as mastics, or sealing compounds, in a wide range of industrial and commercial fields such as construction, footwear, and the automotive industry. Generally deposited as thick films, SRAs behave as structural adhesives; their low elastic moduli accommodate large strains between the bonded parts without incurring permanent damage. Other outstanding attributes of SRAs are their resistance to solvents, their ability to withstand aggressive environments, and their ease of use. This article discusses examples of SRAs and, more specifically, shows how the cross-linking chemistry, mainly through step-growth polymerization, provides their primary advantages.

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