Lightweight Fuel Efficient Engine Package

Brittany Borella, Chris Jones, John Scanlon, Stanley Fofano, Taylor Hattori, and Evan See

Project Overview

Customer NeedsCustomer Need

# Importance Description

    Engine

CN1 1 The engine must reduce fuel consumption when compared to the previous engine package

CN2 1 The engine must provide sufficient power output and acceleration

    Control System

CN11 2 The control system must provide accurate fuel delivery and measurement

    Cooling System

CN14 1 The cooling system must be able to allow the engine to operate in high ambient temperatures under race conditions

    Documentation and Testing

CN17 1 Documented theoretical test plan and anticipated results

CN18 1 Must provide a CFD analysis of the intake manifold, restrictor, and throttle

CN19 2 Must provide an accurate model of the engine in GT-suite

Engineering SpecificationsSpec. # Importance Source Specification

(metric)Unit of

MeasureMarginal

ValueIdeal Value Comments/Status

S1 1 CN1 Fuel Consumption km/l 6.9  8.3 Want to use ~0.7 gal for the

22km run

S3 1 CN2 Power Output HP 45 55  

S4 1 CN2 Torque ft-lbs 31 35  

S6 1 CN4,15 Reliability km 50 100Should be able to perform in all Formula SAE events and

testing before major overhaul

S8 1 CN6 Weight lbs 75 68 Engine weight 

S9 1 CN8 Fuel Type N/A     E85 Ethanol-Gasoline Blend or 100 Octane Gasoline

S12 1 CN14 Temperature °F 220  200

Cooling system must keep the engine under 200 degrees in ambient temperatures up to

100 degrees

Engine Model

Air/Fuel Ratio: 0.86 Lambda Simplified tubular geometry used for initial induction and exhaust models CRF250R valve flow scaled until WR450F data is measured Wiebe combustion model parameters currently estimated until cylinder

pressure data is obtained Ignore effects of muffler Surface roughness values estimated Wall heat transfer properties estimated for steel exhaust sections Intake and exhaust valve lift estimated from YZ400F until actual

measurements can be made Assume constant operating temperature and component temperatures—to be

correlated with dyno data Assume ambient conditions of 14.7 psia and 80°F

Overall Assumptions

Finalized intake/throttle/restrictor geometry Finalized injector placement(s) Injector flow data Intake/exhaust valve inflow and outflow loss coefficients Intake/exhaust cam profiles Base cam timing General cranktrain dimensions Surface area ratios for head and pistons P-V Diagrams to validate Wiebe model assumptions Various temperature measurements

Required Parameters

Theoretical Engine Model

Live Simulation of Engine Parameters

Dynamometer Test Stand

Cylinder Head Removed for Measurement

Photo Courtesy of DUT Racing

Bore Tube Production

Flow Testing of Cylinder Head

System Test Plan

Engine Characterization Torque P-V Diagrams Brake Specific Fuel Consumption Cooling System

Sensors Cylinder Pressure Crank angle Thermocouples Fuel Flow Coolant Flow Basic Engine Diagnostics Wideband Lambda

Engine Testing

FT-210 Series Gems Sensors & Control 0.026 - 0.65 gal/min ± 3% Accuracy

Fuel Flow Sensor

PCB Piezotronics Transducer 112B10 422E In-Line Charge Converter

Cylinder Pressure Sensor

AM4096 - 12 bit rotary Measure Angular Position Outputs

Incremental Series SSI Linear Voltage Analogue Sinusoidal

Magnetic Encoder

Load Simulation Power Characterization Fuel/Spark Mapping

Dynamometer

Dynamometer Controller Data Input Improvement

NI PCI-6024E 200 kS/s 12-Bit 16-Analog-Input DAQ

Data Acquisition

CFD Analysis

20 mm inlet diameter (19 mm for E85) creates choked flow conditions, limiting total mass airflow to engine Required by competition rules Keeps engine power at a safe level for competition

Design goal is to minimize loss coefficient through restrictor geometry to allow maximum airflow into engine

Supersonic Converging – Diverging Nozzle Geometry Expand out diverging section to allow for proper shock development to

minimize loss coefficient Keep diffuser angle low enough to avoid potential flow separation Keep overall length low to reduce viscous losses due to surface friction and

boundary layer growth

Intake Restrictor

2-Dimensional Axis-Symmetric analysis allows for fast solving time with refined mesh in areas of shock development

Intake Restrictor

Air flows from throttle to engine intake port through intake manifold

Intake Plenum Acts as air reservoir for engine to draw air from during intake stroke Primary purpose is to damp out pressure pulses from intake stroke to create

steady flow conditions at the restrictor Intake Runner

Path through which engine pulls air from the plenum into the combustion chamber during intake stroke

Length decided by harmonic frequency at various engine operating speeds, can be used to create a resonant “tuning point”

Intake Manifold

Transient Pressure Boundary Condition used to simulate pressure pulses within manifold from intake stroke Piecewise-Linear Approximation used for initial analysis trouble-shooting End analysis will use pressure trace measured during Dynamometer Testing

Intake Manifold

Component Simulation Shroud structure analyzed to ensure uniform airflow distribution across

radiator face and verify proper mass airflow through radiator Radiator modeled as a material resistance with heat addition and flow re-

direction to properly simulate airflow through core

Cooling System Airflow

Full Car Simulation to verify shroud is receiving adequate airflow Simulation model still in progress, needs additional geometry and refinement

Cooling System Airflow

Cooling System

Cooling System Schematic

Surge Tank

Overflow Tank

Steam from Cylinder Head

Engine Block Water Pump

Fan

Radiator

Thermostat

Rule of thumb: 1.1 in2 radiator surface area needed per hp produced Therefore need approx. 66 in2

Radiator from YFZ450R Yamaha ATV 7.5” H x 11.5” W x 7/8” D Surface Area 86.25 in2

Inlet and Outlet ¾” ID tubing to connect to water pump

Radiator

Outlet to Water Pump

Inlet from Engine

Modify for bleed line to Surge Tank

Coolant naturally builds to approximately 16-18 psi Normal production cars run 16-18 psi, high performance cars

run 22-24 psi , and racing systems run 29-31 psi Pressurizing the water allows for the water to reach a higher

temperature before boiling (therefore vaporizing) Part# T30R Radiator Cap 29-31 PSI

Pressure (PSI) Boiling Point (° F)0 PSI 212° F10 PSI 239° F20 PSI 259° F30 PSI 273° F40 PSI 286° F50 PSI 297° F

Radiator Cap

Typically a 1 quart container Need to modify the part of the

Radiator that currently has the cap and overflow line to run a ¼”- 3/8” bleed line from radiator to top of surge tank

½” – ¾” Refill line from bottom of surge tank to inlet of water pump

Benefits – de-aeration 2% air in the system leads to an 8%

decrease in cooling efficiency 4% air in the system leads to a 38%

decrease in cooling efficiency!

Surge Tank

Bleed line inlet from radiator and cylinder head

Outlet to overflow tank

Refill line back to water pump

30 PSI Pressurized Radiator Cap

Comes stock on engine No internal bypass system.

Thermostat will have to regulate continual water flow through engine

¾” ID inlet and outlet tubing to connect to radiator

Water Pump

Flow Rate vs. RPM from R6 water pump

Need to test flow rate once we have the cylinder head again

Placed at the outlet of the engine, a thermostat allows water to circulate through the block, but doesn’t allow this water to circulate through the radiator until it has reached proper operating temperature

This temperature (195°F) melts the “wax motor”, which forces the thermostat piston to open and allows the water to flow through.

If the engine’s temperature is lowered too much, the piston closes until it has reached proper operating temperature once again

Thermostat

Stewart/Robert Shaw Thermostats – 302 Augments bypass system $14.95

Cooling System Data

Reviewed three sets of autocross runs with different drivers

Verify radiator is receiving adequate airflow at low speeds

SPAL Axial Fan 11” Dia. 755.0 CFM

Based on predicted power require minimum 450 CFM

Based on airflow at speed available require minimum 500 CFM

Maximum 7” Dia. to fit radiator Yamaha R6 Fan

5.5” Dia. Est. >500 CFM

FanF19 F20

mph ft^3/m ft^3/m50 0 05 213 13010 426 26015 639 39120 853 52125 1066 65130 1279 78135 1492 91240 1705 1042

Q = required heat rejected into air

Risk Assessment

Risk Assessment - TechnicalID Risk Item Effect Cause L S I Action to Minimize Risk Owner

Technical Risks

1 Engine Dynamometer not reliable

Unable to characterize

engine torque

Dynamometer control system

not reliable2 2 4

Be familiarized with the Dynamometer control programs. Attempt to

characterize the Dynamometer and create

an accurate control system in case the original is

inefficient.

Stanley Fofano

3 Insufficient Cooling of the Engine

Engine Overheats/damag

e to engine

Cooling system undersized or

inefficient2 3 6

Correctly analyze cooling system to maximize

efficiency

Evan See, Brittany Borella

4

Unable to accuractly predict airflow through

the intake manifold, restrictor, and throttle

Inaccurate theoretical model

of engine

Improper CFD analysis 2 2 4

Accurately control initial assumptions and

conditions in order to create the most accurate

model possible

Taylor Hattori

5

Unable to accurately predict fuel

consumption and power output

Inefficiencies in the engine package

Improper Engine

Modeling2 3 6

Verify engine model with dynamometer testing in correlation with fuel flow

sensors.

John Scanlon

8 Air:Fuel Ratio too lean Damage to engine

Ratio leaned out too far in

order to increase fuel

economy

2 3 6Slowly change the air fuel mixture in order to realize

effects before another change is made

Chris Jones, John Scanlon

Risk Assessment - ManagementID Risk Item Effect Cause L S I Action to Minimize Risk Owner

Project Management Risks

10 Insufficient funding

Outside contracted work

won't be able to be paid for

Outside Contracting work is expensive 1 1 1

Use funds wisely and try to do as much in house testing as possible. When outside testing is necessary,

try to take advantage of sponsorships.

Brittany Borella

11Inconsistant

Team Priorities

Actual Senior Design

deliverables do not get met

Actual engineering in the project given more

priority than Senior design paperwork and

deliverables

1 1 1

Project Manager(s) in charge of keeping track of all deliverables, for

the class and the actual engine design, and making sure they are

being taken care of by everyone on the team

Evan See, Britttany Borella

12Project not

completed on time

Formula team does not have a complete engine

package

Poor time management and planning 1 3 3

Lead engineer will make sure that sufficient time is put into all engine systems so that all components are properly tested and prepared for the

final engine package

John Scanlon

13Parts are

ordered too late

Engine Dyno testing and on car testing cannot be completed on time

long lead parts not identified and ordered

on time1 2 2 Long lead time parts ordered as

soon as identified - early in MSD1 John Scanlon