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USING TEMPLATE DRIVEN CFD TECHNOLOGY FOR

ADVANCED AUTOMOTIVE AND MARINE

APPLICATIONS

• AGENDA – ‘NAFEMS UK - 18th July 2018’

• Brief Company Overview – 80/20 Engineering Ltd

• Democratization – Best Practises in the CFD Process• Template Driven CFD Technology

• Meshing Strategy – Binary Adaptive Tree (BAT)

• Advanced Automotive Applications

• Advanced Marine Application

• Conclusions

• Appendix• Published Papers


80/20 Engineering

• The Value 80/20 Engineering delivers:

– Design Engineers need to evaluate many concepts quickly and easily, so need a real alternative to traditional physical testing…

• CFD/CAE tools for Product Development

– Some Flow/Thermal/Structural applications are very complex in nature and often companies just don’t possess the resources and/or competencies to perform in-house simulation….

• High Level Simulation Consultancy


Some of our Customers

QinetiQ - Delivering Customer Focused Solutions


Machinery Specific Templates

• Flow, Pressure, Heat, Species, Particles

• Aeration & Cavitation: Non-Condensables / Vapor / Compressibility

• Volume Motion and Deformation: Rotation / Translation / Scaling

• Automated Binary-Tree Mesh & Implicit Matching Across Interfaces (MGI)

• Engineering Output: Points / Integrated Data (Volumes & Surfaces)

A T

em

pla

te S

tru

ctu

re

Pistons Crescent /Gerotor Vane / VDVP

ValvesRolling PistonScroll Compressor

Spur (External) Gear Axial / Centrifugal Progressive Cavity

http://www.simerics.com/gallery_radialpiston_pump.html

http://www.simerics.com/gallery_ball_valve.html

http://www.simerics.com/gallery_doubleinlet_pump.html


• Multiple moving parts: PD pump, control

valve and dynamic bearing

amplified

Real size

Dhar, S., Afjeh, H., Srinivasan, C., Ranganathan, R. et al., "Transient,

Three Dimensional CFD Model of the Complete Engine Lubrication

System," SAE Int. J. Engines 9(3):2016, doi:10.4271/2016-01-1091.

Location Idle Peak Torque Rated High Idle

Pump Outlet 2.16% 1.23% 5.87% 3.35%

After Cooler 4.64% 0.00% 3.62% 2.76%

After Filter 3.28% -0.54% 3.75% 3.74%

Main Gallery 2.13% -1.85% 2.36% 3.04%

Pressure: Difference between prediction and experiment

Gap amplified

Advanced Automotive Applications

- Lubrication Systems


• Multiphase flow transient simulation

with air and engine oil

• Crankshaft, camshaft, complete gear

train, piston motion are modeled

• Intermeshing gear teeth


- Crank Case


Delivers SPEED

in terms of set-up

and run times

whilst retaining

model DETAIL

Mesh Generation for Template Usage

A Binary Adaptive Tree mesher can mesh very complex

geometries and accept CAD geometry with flaws as illustrated

by the following example:

Binary Adaptive Tree

Combines CARTESIAN

Structured mesh and

unstructured

POLYHEDRAL cells

near complex features



• Vehicle Template - Front End Air Flow

Objectives

• Perform numerical experiments to replicate wind tunnel testing

• Determine for different vehicle speeds, fan speeds, grille or shutter shapes, structures,

license plate configurations, the air flow rates through the grille, condenser, radiator

and fan modules

• Determine the pressure distribution through air induction system

• Under-hood thermal simulation


Binary Adaptive Tree Mesh

Shutter Grille Movement

Active Grille Shutters (AGS)

Vehicle Template - Front End Air

Flow


Velocity & pressure

Front End Flow

Metrics: Model Setup and Run

~ With Simerics-MP: “As is” CAD → Computational run: 2 – 3 hours

~Previous CFD Process: 3 – 5 weeks

~ 50 million cells

~ Run time: ~ 16 hours with one 8-core processor*

* Subsequent Simulations: Starting from previous solution takes 4 hours

~ Previous CFD Process : ~ 16 hours with 64 processors (Benchmarking done by our customer)

Template Driven Advantages


Flow



Flow

Car Operating Condition Difference with Experiment [%]

Vehicle 1Speed A 1.5

Speed B 4.3


Speed B 5.1


Speed B 1.9

• The Vehicle Template predicted flow through the CRFM (Condenser, Radiator, Fan Module) as compared to wind tunnel experiments.


Full Vehicle Conjugate Heat Transfer Study

Challenges uniquely handled by Template Driven CFD Technology

❖ Full vehicle Conjugate Heat Transfer with 3D cells inside all solid components.

▪ Extremely Complicated CAD, contains 1000’s of solid components

❖ Quick mesh generation with automatic creation of interface between fluid and solid

components.

❖ All solid temperatures are calculated accounting for all 3 modes of heat transfer :

conduction, convection and radiation.

❖ Mesh adapts to small gaps, holes and captures the small features of the geometry

Underhood Underbody Thermal

Objectives

▪ Problem: Heat transfer is driven by hot exhaust gases flowing through the exhaust system into

the atmopshere

▪ Analysis Goal: Perform full vehicle (under-body and under-hood) thermal conjugate heat transfer

simulation with surface-to-surface radiation

▪ Importance: Understand peak temperatures on solids to ensure material integrity at high

temperatures


Process

1. CAD Preprocessing 4 (manual)

2. Mesh Generation (87 M cells) 6

3. Model Pre-processing 16 (manual)

4.ARadiation S2S view factor

calculation8

4.B Simulation run (500 iterations) 48

Total6 calendar

days

Man Hours2.5 working

days

Full Vehicle Conjugate Heat Transfer Study: Metrics

Underhood Underbody Thermal

Heat transfer


Vehicle Driving through a Water Pool Air Induction System

Dirty Side

Clean Side

Model Formulation

Problem: Vehicle drives through a pool of water, at varying speeds

and water pool depths

Analysis Goal: Determine if the air suction to the engine will pull

water to the clean side of the air filter

- Can Vehicle Template Technology replicate water-tunnel test?

Why Important: In off-road vehicles, water fording test is important for

the durability of the engine

Vehicle Water Fording

Water Fording


Air Induction System

Vehicle Water Fording

Water Fording


Template Driven Simulation for

Advanced Marine Applications:


DTMB 5415 – Validation Study

-1.5

-1.0

-0.5

0.0

0.5

0.0 0.1 0.2 0.3 0.4 0.5T

rim

(d

eg)

Fr

Trim

0

2

4

6

0.0 0.1 0.2 0.3 0.4 0.5

Sin

ka

ge/

Lp

px1

03

SinkageCFD

Experiment

0.003

0.004

0.005

0.006

0.007

0.008

0.0 0.1 0.2 0.3 0.4 0.5

CT

Drag Coefficient CT

Marine Applications –

Displacement Hull Drag, Sinkage

and Trim

‘2017_SNAME_Prediction of Planing Hull Resistance and

Porpoising using a RANS-based CFD Tool’


Marine Applications –

C-Fury Rib

• A 80/20 Engineering case study illustrating

the capabilities of the Marine Template using

CFD simulation of a C-Fury Rigid Inflatable

Boat (RIB) is now presented.

• This model was run as a two-phase flow

simulation using the Simerics Marine

Template. The model is first accelerated from

0 to 8 knots and then from 8 to 15 knots.

19


Marine Template –

Geometry

The geometry of the RIB was supplied by C-Fury as a Rhino .3dm file. This was

read directly into our SpaceClaim model preparation tool.

20


Marine Template –

Model Preparation• The surface geometry of the hull needed minor repair

• converted to a solid by adding a deck surface.

• The hull geometry was then combined with the hydrofoil surfaces.

• The surfaces were also named to be recognised in Simerics.

• STL files were then produced to transfer to Simerics.

• These files could have been produced directly from Rhino.

21


Marine Template

- Meshing

The .stl file of the hull was read into Simerics

MP and the surfaces created were selected

for the Marine Mesh Template. A medium

resolution mesh refinement setting was

selected and the minimum cell size was

reduced in order to capture the fine details in

the hull shape.

The meshing template also requests the

movement direction and the centre of gravity

so it can determine a suitable mesh pattern.

The size of the domain around the vessel can

also be specified. Most of the domain size

and mesh size settings can be left to default if

the user is uncertain of what values to use.

22


Marine

Template

- Meshing

23

The resultant mesh

contained 4,653,126

cells with 15,607,078

faces. The template

ensures that this is

concentrated around the

hull and in the wake

region as illustrated

here.


Marine Template - Set-up

For this type of two phase flow

simulation the solution parameters are

also entered via the marine template.

The additional quantities required at

this stage are the target velocity and

the mass of the vessel. The other

quantities shown in the panel on the

right can also be adjusted.

For the initial case the target velocity

was set to 8 knots with a ramp up time

of 1 second. Once this initial

simulation was completed the velocity

was then increased to 15 knots and

the solution was restarted.

24


Marine Template - Solution

• The solution is run as a transient. All the controls are set by the template described on the previous slide.

• The first stage of the solution, to accelerate the Rib to 8 knots, took approximately 14 hours to run on a Dell Precision 7520 laptop with a seventh generation Intel i7 processor.

• The second stage (from 8 to 15 knots) took longer to settle so took approximately 24 hours to run the transient to a total of 12 seconds.

25


0 to 8 Knot Transient26


CONCLUSIONS

• Summary:

– Advanced Template Driven CFD Technology

Presented

• Fluid Machinery Background

• Expanding Automotive Applications

• Marine Applications

• Thank you for your time

• [email protected]

• Mobile: 07879 432669

• Office Tel: 01494 616020

• www.8020engineering.com

mailto:[email protected]

http://www.8020engineering.com/


Appendix - Published Papers

Simerics Actively Participates in Academic Activity


80/20 Engineering

•The Pareto Principle, often called "The 80/20 Rule", means that in

anything, the few (20 percent) is usually responsible for the many (80

percent).

•Application to the Engineering ‘Simulation’ Process

– 80% of business value delivered by 20% of analysis resources

deployed for simulation.

• Critical that simulation resources are used in an optimum

way

•Focus on Product Development

– 80% of product performance, or project success is defined by 20%

of the development life-cycle.

• Critical that performance information is available at the

earliest opportunity.

using template driven cfd technology for advanced ... · nafems world congress 2015 | 21nafems uk...

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