A High Performance, Continuously Variable Engine Intake Manifold Adam Vaughan The Cooper Union Albert Nerken School of Engineering 2010 Master’s Thesis SAE Papers &

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 Continuously Variable Half-Tube Design (measured from back of valve)

Restrictor Fuel Rail Servo Rubber Mold of Intake Port Variable Runners Static Runner © 2009 FSAE ® Rules Overall Layout

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 diameter ❷ Inlet taper angle ❸ Outlet taper angle ❹ Outlet diameter Restrictor Variables ❶ Inlet diameter ❷ Inlet taper angle ❸ Outlet taper angle ❹ Outlet diameter D D o o E E 2D Axisymmetric Steady State Restrictor DoE Outlet taper angle Inlet taper angle Inlet diameterOutlet diameter symmetry 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 Simulated Torque (N·m) before experimental data were available Torque Contours at WOT

Measured Torque (N·m) preliminary engine calibration, unoptimized cams Measured Torque at 9,500 RPM preliminary 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