Formulation

STAKEHOLDERS

The primary stakeholders for our project include the Panther Motorsports, Florida International University, and SAE. While the Panther Motorsports team are our main stakeholders and require a the functional intake design, FIU also plays an important role since Panther Motorsports represents the FIU's student body engineering prowess and innovation. Additionally, we have secondary stakeholders such as the Panther Motorsports' sponsors and the automobile/manufacturing industry companies that will be attending the FSAE competition.

In the slides below, we explain more in detail about each of our stakeholders. (Scroll-down to see all )

stakeholders.pptx

Systems Analysis

Our project system is broken up into two main sections those being:

The intake manifold itself, which includes the neck, the plenum, and the runners and deals with the intake geometry and performance.
The intake mounting which includes the mounting system of the intake and the engine to ensure secure mounting and legality with the technical regulations.

Thermal Performance: Durability of intake manifold to withstand all thermal cycles from engine.
Material and Manufacturing: Refer to material selection design matrix, optimum material selection discussed there.
Fluid Performance: Increasing the amount of air your intake can push into the engine, will directly correlate with increasing horsepower.

GLOBAL ASSESSMENT

Market Assessment

While our intake design is specifically made for the FIU FSAE teams vehicle and engine setup, our research, documentation, and analysis of a two cylinder intake manifold will be a useful tool for other FSAE teams across the globe to utilize. In the future, other FSAE teams who have purchased the same engine, can have research and proven data available so they can apply to their teams design. This will allow us to expand the market, as most University teams are on a time constraint, meaning they will opt in to purchase the Kawasaki Ninja 650 cc engine, and implement our specific Intake manifold design. Which will bring in a lot more attention to FIU Engineering program and Panther Motorsports.

Global Need

FSAE is a global competition design series, that allows students to push boundaries of creativity and innovation in the automobile industry, while providing students from all backgrounds the opportunity to learn, develop their engineering process, and display their solutions out on track and in front of experienced engineers for hands on feedback and career opportunities. One big advantage of designing while in FSAE is the fact that students are free to create without any limitations or preconceived knowledge from previous experience, that you would face in real world engineering jobs. In other words, they can let their imagination run free. This is also beneficial to different companies, as they can gather fresh new ideas and ultimately give FSAE students jobs. Lastly, students get the chance to see their in classroom theories come to fruition, which allows them to gather more knowledge and experience.

LITERATURE REVIEW

WHAT IS FSAE?

Formula SAE is an engineering design competition where many international universities participate. It is proposed from the Society of Automotive Engineers (SAE), and it consists in the development and production of a racing vehicle that is evaluated through a series of different challenges based on the quality of the project and engineering efficiency.

Established in 1981 with the main objective of giving engineering students the possibility of applying the gained knowledge during the year of study. The competition is globally recognized, with different annual events directly organized by SAE, various other engineering association, and automotive companies. The competition consists of various sub-competitions on which team will be judged based on a point system. Sub-competitions for Formula SAE are subdivided in two main categories:

· Static: Include competitions such as Cost Analysis, Business Plan Presentation, Engineering Design.

· Dynamic: Consists of competitions such as Acceleration, Skid-Pad, Autocross, Endurance and Fuel Economy. [6]

FOUR-STROKE IC ENGINE

An internal combustion (IC) engine is a type of heat engine where the spark of the combustion occurs inside the engine, therefore the name.

The process occurs as the piston goes through 4 stages or strokes repeatedly:

Intake Stroke: As the piston goes down, the intake valve opens letting air mix with fuel, since the injector valve opens simultaneously to let the fuel in.
Compression Stroke: The air and fuel mixture is compressed by the piston moving upwards, while the valves are fully closed.
Power Stroke: A spark ignites the mixture in the combustion chamber, combustion occurs and temperature is increasing. The piston goes down as exhaust gasses are produced.
Exhaust Stroke: Exhaust valve opens, piston pushes out burned gasses.

For the scope of this project, we are focusing on the system that facilitates the air coming in during the intake stroke and distributes it to the engine's pistons, the intake system. [4]

INTAKE SYSTEMS

An intake manifold is a fundamental system for an internal combustion (IC) engine. It serves as a reservoir of air that ensures an equal and uniform distribution of air into each of the engine’s cylinders, by directing the air from the surrounding into the combustion chamber.

The intake manifold consists of two main components:

1. Plenum: the large cavity at the top of the manifold.

2. Runners: single tubes connecting the plenum to the cylinder head.

Air enters the engine starting from the air filter to the throttle with the FSAE restrictor placed right after in the case of our project, and then finally enters the intake manifold and gets delivered to the engine.

simulation overlay.mp4

The main principle behind the functioning of an intake manifold is Helmholtz Resonance, in which air flowing through the open valve at high speed starts accumulating and forming an area of high pressure against the valve once the valve closes. At this moment, high pressure areas start equalizing with low pressure areas in the manifold. High and low pressure areas interchange within each other in an oscillatory manner. This process occurs at speed of sound, with air traveling up and down the different pressure areas in the manifold many times before the valve opens again.

Optimal volumetric efficiency is dictated by an optimal design shape of the manifold. For instance, a design with abrupt contours may result in pressure drops that may have repercussions on the combustion process of the engine. Therefore, smooth contours are usually preferred for a typical intake manifold design.

By implementing the use of a 20 mm restrictor on the competing 4-stroke engine, the mass flow of air going through the engine becomes restricted and power is consequently reduced. This requirement must be carefully analyzed and ensure that the engine is being supplied the maximum amount of air possible for maximum volumetric efficiency with minimum pressure drops across the intake manifold, therefore the design of the intake system becomes very important.

INTAKES USED BY FSAE TEAMS

FSAE teams currently run a variety of different intake manifolds types , ranging from variable intake manifolds with changing runner lengths and diameters, dual plenum, dual runner intakes and the standard fixed intake manifold. The main reasoning for the variable and dual intake models is to have the ability to change the engine maximum torque and power output transiently throughout the lap by modulating intake runner lengths, diameters, and even plenum size. Variable intake manifolds bring a good advantage to competition that many other more experienced and well funded teams implement to their designs.

However, there are many teams within the FSAE standings that have won competition or placed high in rank with regular fixed intake designs, this is because most racing cars stay within a certain RPM range that the maximum torque and power lies, a fixed intake can be tuned to this range and still be effective for the majority of the lap. Variable intake manifolds are also high complex due to the difficulty of sealing moving parts between and sealed volume and the outside atmosphere, also the movements have to fast enough to change with the engine speed, this typically ends up requiring pneumatic and electronic systems which add weight and extra failure points to the intake system.

Since Panther Motorsports does not have a current working intake design our focus for this project is to provide the best fixed intake manifold possible for the current PM22 engine setup, track layout, and vehicle. Since this will be the first intake utilized by the team for the Kawasaki 650 Engine we hope our research and design will be use to set up an initial foundation that can be built upon to a more complex intake design such as a variable intake manifold.

Fixed Intake Manifold

Variable Intake Manifold

Dual Plenum Intake Manifold

PERFORMANCE INTAKES USED ON THE MARKET

Roush Racing Ford GT Composite Intake

LSX Dual Plenum Cross Ram Intake

Porsche 997 GT3 Modular Intake

There are many features to consider while designing a performance intake manifold, ranging from cross-sectional area, length, taper angle, and shape of the intake run. One of the most important things to consider is the shape and volume of the intakes manifold. Larger-area runners will improve the flow at higher engine speeds but may also slow the filling of the cylinders at lower engine speeds. Longer runners will sometimes impact the power and torque production at lower engine speeds while shorter runners may move the peak torque rpm higher up. As you create the ideal shape and taper the angles of the runner you will maximize the performance for a given runner length and area. The shape and size of the plenum allow for a good transition from the throttle body to the intake runners.

CONSTRAINTS & OTHER CONSIDERATIONS

TIME CONSTRAINTS

The intake manifold is required for the current Panther Motorsports car, to attend the FSAE competition held in Michigan during the week of May 18th, 2022. This means that for this project, we not only need to follow the Senior Design timeframe, but in addition, we need to take into account the Panther Motorsport's plan of action and deadlines.

Panther Motorsports needs a functional intake prototype by the end of February 2022, in order to perform in-vehicle testing with the complete vehicle as if it was ready to compete. Thus, this is our main deadline to meet. The final design must done by April, 2022, which will be before the competition and on time for the Senior Design Showcase.

Due by to this time constraint, we are doing a fix intake design with no variable intake runner length or variable intake diameter. Making this decision, allow us to reduce the complexity of the design and ensure that we can initially find an intake design that bring maximum engine performance at the desired RPM range. Hopefully, our project will be later looked upon and used for the development of a variable intake unit to increase the performance band of the engine.

FSAE RULES

FSAE offers a series of guidelines and regulations that must be met for the students to participate in the competition. The main objective of this regulation is to ensure safety and limit performances. Besides the fact that the competing team must be formed by university students only and can only receive advice from either professionals or professor, the competition imposes specific rules on various aspects of the vehicle, such as:

· Engine

· Suspensions

· Aerodynamics

· Safety related to driver and vehicle

These rules are issued under the authority of the SAE International Collegiate Design Series for every calendar year of the competition, and can be found on the FSAE website. As a participating team, Panther Motorsports and its vehicle must comply and be bound to all the rules and standards stablished by FSAE.

Since the focus of this project lies on the design of the intake manifold, we extracted the parts of the rulebook that are applicable and must to be follow, to ensure that our intake system design will successfully satisfy all of them. It is important to point out, that FSAE encourages the designs to be creative within the boundary of the rules, and the our team has freedom went it comes to the design decisions of the optimal model.

The rules and constraints pertaining to our design can be found in the drop-downs below.

Intake System Location and Packaging

All parts of the engine air system and fuel control, delivery and storage systems (including the throttle or carburetor, and the complete air intake system, including the air cleaner and any air boxes) must lie inside the Tire Surface Envelope (which is the volume enclosed by tangent lines between the Main Hoop and the outside edge of each of the four tires). [7]

Intake System Mounting

The intake manifold must be securely attached to the engine block or cylinder head with brackets and mechanical fasteners. Hose clamps, plastic ties, or safety wires do not meet this requirement. The use of rubber bushings or hose is acceptable for creating and sealing air passages, but is not a structural attachment.
Threaded fasteners used to secure and/or seal the intake manifold must have a Positive Locking Mechanism
Intake systems with significant mass or cantilever from the cylinder head must be supported to prevent stress to the intake system.

a. Supports to the engine must be rigid.

b. Supports to the Chassis must incorporate some isolation to allow for engine movement and chassis flex. [7]

Intake System Restrictor

All airflow to the engine(s) must pass through a single circular restrictor placed in the intake system.
The only allowed sequence of components are the following:

a. For naturally aspirated engines, the sequence must be: throttle body, restrictor, and engine.

b. For turbocharged or supercharged engines, the sequence must be: restrictor, compressor, throttle body, engine.

The maximum restrictor diameters at any time during the competition are:

a. Gasoline fueled vehicles 20.0 mm

b. E85 fueled vehicles 19.0 mm

The restrictor must be located to facilitate measurement during Technical Inspection.
The circular restricting cross section must NOT be movable or flexible in any way.
The restrictor must not be part of the movable portion of a barrel throttle body. [7]

Connections to Intake

Any crankcase or engine lubrication vent lines routed to the intake system must be connected upstream of the intake system restrictor. [7]

COST AND FUNDING

Cost and funding are constraints in any project, currently for our project we are utilizing the help of several Panther Motorsports Sponsors to provide PLA filament for 3D printing and 3D printing services to print the intake in other materials such as Ultem, Nylon, and other high temp materials. The amount of prints we can make from the higher end materials will be limited so those allocations will be reserved for some prototypes that the team can run on track and the final intake design that will be used for competition. The amount of prints that will be allowed have not been finalized yet, as we are working with the sponsors to negotiate the number of prints.

KEY DESIGN REQUIREMENTS

Intake Design Theory

Intake design theory stems from both Helmholtz Resonator Theory and Ram Theory. Where the main focus is to increase the engine output by increasing volumetric efficiency of the engine. The picture to the left is an example of both Helmholtz and Ram theory where a resonator acts as a spring to bounce back the pressure wave created by the intake valve back into cylinder.

RAM Theory Diagram

Runner Length and Ram Effect

Runner lengths effect the resonance tuning of the engine and can push the peak engine torque and power to certain RPM ranges with long runners you can push the peak engine output to the lower rev ranges, and with shorter runners you can push it to the lower rev ranges. The main goal of adjusting runner length is too get the pressure wave created by the intake closing to come reach the intake port right as it opens, allowing more air to be forced into the cylinder. This is known as RAM theory and can lead to a theoretical 100% Volumetric efficiency for Naturally aspirated engines.

Helmholtz Resonator Theory Diagram

Plenum Volume

Plenum volume is needed to act as a type of pneumatic spring for the pressure wave created when the intake closes to create an effective RAM theory runner. The plenum volume also ensure that the engine does not experience choked flow at higher RPMS due to the 20mm restrictor. Increasing plenum volume typically leads to higher maximum power output but at the cost of throttle response as the air reaching to the cylinders is too slow due to the high expansion created by the large volume. In the case of the intake manifold the plenum acts as a resonator/ collector where the majority of the air mass that passes through the restrictor is stored. Typically the pressure in the plenum would ideally be at atmospheric pressure as this allows the resonator to be as stiff as possible and reduce any losses the to the pressure wave due to dampening. The plenum volume is also important to keep the pressure wave from the two cylinder separated so they do not interfere with each other.

Intake Manifold Cross Section

Runner Diameter

Runner diameters play a major role in how the pressure wave propagates throughout the intake runner and affects the overall speed of the airflow within the pressure. Typically smaller runner diameters improve throttle response as it helps increase air velocity to the runners, but is also more susceptible to chocked flow at higher RPMS.

Mounting and Sealing

The sealing and mounting of the intake is a key design requirement as we must satisfy all rule and regulations outlined in the constraints and consideration section. The intake must also be properly sealed to work and isolated from major vibrations to retain structural integrity throughout competition.

Page updated

Report abuse