Difference between revisions of "Exhaust"
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| − | The '''exhaust''' system is designed to aid in the removal of burnt fuel and air from the engine. A sound limit is placed on the exhaust in competition. | + | The '''exhaust''' system is designed to aid in the removal of burnt fuel and air from the engine. A sound limit is placed on the exhaust in competition. |
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[[File:Exhaust diagram.PNG|thumb|Exhaust System]]<br /> | [[File:Exhaust diagram.PNG|thumb|Exhaust System]]<br /> | ||
| − | + | =Exhaust Form Factors= | |
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The exhaust form factor should drop out of your design constraints (e.g. packaging and weight) as well as your engine system model. There is no one right answer for the best exhaust system.[[File:Exhaust mounting diagram.PNG|thumb|Exhaust Mounting]] | The exhaust form factor should drop out of your design constraints (e.g. packaging and weight) as well as your engine system model. There is no one right answer for the best exhaust system.[[File:Exhaust mounting diagram.PNG|thumb|Exhaust Mounting]] | ||
| − | + | ==4-1== | |
| − | + | '''Pros''' | |
| − | + | * Simplicity | |
| − | + | * can do the thing wherfe you clock all 4 runners to time the pulses and always have a low pulse a the collector when a high pressure pulse is coming out of the engine | |
| − | + | '''Cons''' | |
| − | + | * 4 to 1 collector can be hard to source, or manufacture depending on your team's resources, | |
| + | * Can only tune to one frequency | ||
| + | ==4-2-1== | ||
| + | '''Pros''' | ||
| + | * can tune for two resonant frequencies | ||
| + | * more flexibility with packaging | ||
| + | ==4-2== | ||
| + | I know it's been done by at least one team but for the life of me I can't find them | ||
| + | ==4-4== | ||
(never seen 4-4 but it'd be sweet. A drawback would be having to include 4 mufflers). | (never seen 4-4 but it'd be sweet. A drawback would be having to include 4 mufflers). | ||
| − | + | {{clear}} | |
| − | + | =Silencers and Noise test= | |
| − | + | ==Muffler/Silencer== | |
| − | |||
A muffler (or silencer) is an acoustical filter designed to ensure appropriate noise control in the exhaust system of an internal combustion engine. | A muffler (or silencer) is an acoustical filter designed to ensure appropriate noise control in the exhaust system of an internal combustion engine. | ||
| − | + | =Manufacturing= | |
| − | + | A key quality control during manufacturing should be maintaining equal runner lengths for each stage of the exhaust and minimizing flowpath disruptions due to weld beads or tube misalignment. | |
| − | + | =Tuning= | |
| − | + | ==Runner Lengths== | |
| − | + | Because of the high temperatures and pressures involved, reduced order models such as Helmholtz (a linear acoustic model) start to break down. A parametric study in WAVE or GT-Power is more useful to determine realistic runner lengths. | |
| − | + | [[File:CooperExhaustRunnerLengthSim.png|thumb|left|Example of the Effect of Different Runner Lengths]] | |
| − | + | {{clear}} | |
| + | ==Helmholtz== | ||
[[Category: Internal Combustion]] | [[Category: Internal Combustion]] | ||
Latest revision as of 14:27, 6 April 2022
The exhaust system is designed to aid in the removal of burnt fuel and air from the engine. A sound limit is placed on the exhaust in competition.
Contents
Exhaust Form Factors
The exhaust form factor should drop out of your design constraints (e.g. packaging and weight) as well as your engine system model. There is no one right answer for the best exhaust system.
4-1
Pros
- Simplicity
- can do the thing wherfe you clock all 4 runners to time the pulses and always have a low pulse a the collector when a high pressure pulse is coming out of the engine
Cons
- 4 to 1 collector can be hard to source, or manufacture depending on your team's resources,
- Can only tune to one frequency
4-2-1
Pros
- can tune for two resonant frequencies
- more flexibility with packaging
4-2
I know it's been done by at least one team but for the life of me I can't find them
4-4
(never seen 4-4 but it'd be sweet. A drawback would be having to include 4 mufflers).
Silencers and Noise test
Muffler/Silencer
A muffler (or silencer) is an acoustical filter designed to ensure appropriate noise control in the exhaust system of an internal combustion engine.
Manufacturing
A key quality control during manufacturing should be maintaining equal runner lengths for each stage of the exhaust and minimizing flowpath disruptions due to weld beads or tube misalignment.
Tuning
Runner Lengths
Because of the high temperatures and pressures involved, reduced order models such as Helmholtz (a linear acoustic model) start to break down. A parametric study in WAVE or GT-Power is more useful to determine realistic runner lengths.
