A High Performance, Continuously VariableEngine Intake Manifold

Adam Vaughan

The Cooper UnionAlbert Nerken School of Engineering

2010 Master’s ThesisSAE Papers 2011-01-0420 & 2010-01-1112

• Improve drivability and increase engine performance:

Variable runner length intake– Wider power band

• Easier for non-professional drivers• Increase low end torque• Keeps top end power

– Simpler and safer than turbo / variable valve timing• > 60% of cars Do Not Finish• Failure mode is a static intake

• Develop calibrated 1D model

Goals

• 20 mm diameter flow restriction– Always at part load

• Packaging envelope• Throttle before restriction• Engine displacement < 610 cc

– Modified Suzuki GSXR-600®– 599 cc, SI, 4-stroke, inline 4-cylinder– DOHC, 16-valve, pent roof– 13.5:1 compression ratio– MicroSquirt® Port Fuel Injection

Constraints

Short Runner Length

Long Runner Length

A New ContinuouslyVariable Half-Tube Design

(measured from back of valve)

Restrictor

Fuel Rail

Servo

Rubber Moldof Intake Port

Variable Runners

Static Runner

© 2009 FSAE® Rules

Overall Layout

2010-01-1112

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Contours of Torque (N·m) % Difference From Baseline

Not Packageable

1D Simulation

Selected design

Gambit® Mesh

Fully automated generation of meshed geometries through

custom Matlab® script or C# GUI

Gambit® Mesh

Fully automated generation of meshed geometries through

custom Matlab® script or C# GUI

Fluent® Simulation

Batch simulation of meshed geometries controlled through

custom Matlab® script or C# GUI

Fluent® Simulation

Batch simulation of meshed geometries controlled through

custom Matlab® script or C# GUI

Restrictor Variables

❶ Inlet diameter❷ Inlet taper angle❸ Outlet taper angle❹ Outlet diameter

Restrictor Variables

❶ Inlet diameter❷ Inlet taper angle❸ Outlet taper angle❹ Outlet diameter

DDooEE

2D Axisymmetric Steady State Restrictor DoE

Outlet taper angle

Inlet taper angle

Inlet diameter Outlet diametersymmetry axis

Choked flow

Contours of Mach Number

Velocity Vectors (m/s)(Along Mid-Runner Plane)

Velocity Contours (m/s)(Along Mid-Plenum Plane)

3D Steady State

Fabricated Intake(using both CNC and 3D printed molds)

• Greatly simplifies the wiring harness → only two wires (CANH & CANL) + GND• Used to send and receive data amongst different controllers (e.g. engine speed)• Up to 1 Mbit/s & noise immune

Controller Area Network

MicroSquirt™ Engine Controller•Executes code for injection and spark timing•Includes built-in injector and coil drivers•Provides CAN interface for real-time engine status & engine control parameter modification

MicroSquirt™ Engine Controller•Executes code for injection and spark timing•Includes built-in injector and coil drivers•Provides CAN interface for real-time engine status & engine control parameter modification

CAN bus

Aft PCB dsPIC® CAN Node•Variable intake control•WiFi™ Telemetry•Power control (e.g. fan PWM)

Aft PCB dsPIC® CAN Node•Variable intake control•WiFi™ Telemetry•Power control (e.g. fan PWM)

Dashboard dsPIC® CAN Node•CAN for signals (e.g. coolant T)•Tachometer / idiot LEDs & LCD•Gear position segment LED

Dashboard dsPIC® CAN Node•CAN for signals (e.g. coolant T)•Tachometer / idiot LEDs & LCD•Gear position segment LED

Traction dsPIC® CAN Node•Traction control algorithm•Measure wheel speed encoders•Retard spark over CAN

Traction dsPIC® CAN Node•Traction control algorithm•Measure wheel speed encoders•Retard spark over CAN

Fabricated Front PCBFabricated Aft PCB

Intake CAN Integration

• Intake servo control using CAN provided engine speed• Fan / coolant pump PWM using CAN provided coolant temp.• Provides gear position over CAN• Centralizes the car’s electric power distribution

— Simple point-to-point wiring harness— Provides fuses and relays

• WiFi™ telemetry

Aft PCB

• Dashboard dsPIC®— Using CAN, it displays through the LCD and LEDs:

• Engine speed from MicroSquirt™• Coolant temperature from MicroSquirt™• Current gear from Aft PCB, etc…

• Traction control dsPIC®— Measures wheel encoders and can modify MicroSquirt™ spark timing over CAN

Front PCB

Torque & Power Curves at WOT

Measured Power (kW)preliminary engine calibration, unoptimized cams

Measured Torque (N·m)preliminary engine calibration, unoptimized cams

Measured Torque (N·m)preliminary engine calibration, unoptimized cams

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Simulated Torque (N·m)before experimental data were available

Torque Contours at WOT

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Measured Torque (N·m)preliminary engine calibration, unoptimized cams

Measured Torque at 9,500 RPMpreliminary engine calibration, unoptimized cams

Transient Response at WOT

• Designed, analyzed and fabricated a functional variable intake– >22% peak power improvement over previous team’s unoptimized static

intake– Empirically demonstrated the ability to shift resonance peak real-time– “More-drivable” engine– <1% increase in powertrain weight

• Implemented a CAN microcontroller network– Intake control, dashboard and traction control

• Developed platform for automated Fluent® studies• Gained experience working with carbon fiber

– Quasi-isotropic FEA for relative improvements

Summary

• Optimize intake cam profile• Additional dynamometer testing

– Fix test stand cooling issues– Measure volumetric efficiency directly– Refine engine calibration– Part load operation & BSFC

• Expand CFD studies– Calibrate Ricardo WAVE® model against dyno data– Perform coupled transient simulations with Vectis®/Fluent®– Integrate gradient based design optimization

• Improve CFRP FEA simulations• Gather actual track data

Future Work

• Friends & Family• Formula SAE®

• Ricardo®, Inc.• Agilent Technologies®, Inc.• Albert Nerken School of Engineering• Cooper Union Student & Central Machine Shop• Cooper Motorsports FSAE® team

Acknowledgements