Difference between revisions of "Fuel"
SpookySimon (talk | contribs) |
SpookySimon (talk | contribs) |
||
| Line 88: | Line 88: | ||
|Spectre | |Spectre | ||
|[https://www.jegs.com/i/Spectre/865/29225/10002/-1 link] | |[https://www.jegs.com/i/Spectre/865/29225/10002/-1 link] | ||
| + | |||
| + | |||
| + | [https://www.highpowermedia.com/Archive/elastomer-compatibility-with-ethanol-in-fuel not compatible with e85] | ||
| + | |||
| + | |||
|} | |} | ||
| + | |||
Revision as of 17:48, 17 May 2020
Internal combustion engines can use a variety of fuels, the fuels available at US competitions are gasoline of octane ratings 93 and 100, and E85. No fuel additives can be used[1]
Contents
Chemistry
Gasoline
Gasoline is typically approached chemically as pure octane.
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 2\text{C}_8\text{H}_{18}(l)+25\text{O}_2(g) \rightarrow 16\text{CO}_2(g) + 18\text{H}_2\text{O}(g) }
if we use atomic weights for carbon, hydrogen, and oxygen, we find that 2 mol of octane is 224 grams, 25 mol of oxygen is 800 grams which comes from 3809 grams of 21 percent air. This yields an air fuel ratio of 17.
Since gasoline is not pure octane and air is not exactly 21% oxygen. Experimentation yields the stoichiometric ratio of 14.7 grams of air per gram of fuel[2].
Ethanol
System Design
Fuel Storage
volume determination
- ways to pick factor of safety
- competition strategy
Tank
mountingmaterialform factor (exterior and interior) sloshing is a meme
Bladder
just pour the gas in a kroger bag and let it flop in the wind /s
Fuel Lines
| Material |
Internal Diameter [in] | Pressure [psi] | Cost [per foot] | Minimum Bend Radius | Supplier | Notes |
|---|---|---|---|---|---|---|
| Hard Lines | ||||||
| Aluminum |
3/8-1/2 |
250 |
2+ | Russell | link
pressure rating is wall thickness dependent | |
| Soft Lines | ||||||
| Nitrile Rubber |
3/8 |
50 |
0.88 | JEGS | link
| |
| Buna-N | 3/16+ | 50 | 1.1 | 1.25 | McMaster | link not compatible with e85 yarn reinforced |
| Buna-N | 3/4+ | 150 | 7 | 3 | McMaster | link not compatible with e85 steel wire reinforced |
| Braided Lines | ||||||
| Nitrile Rubber and Steel |
1/4+ | 50 | 3.50+ | Spectre | link
| |
Hard Lines
only legends do this [citation needed]
+weight
- cost
-manufacturing
+pressure
- not as reusable year to year
Soft Lines
pressure and solvent rated
e85 sucks for this
+cost
+manufacturing
+reusable year to year / design to design
-pressure
Braided
you're gonna poke you're eye out kid
- cost
- mfg
- i hate
+ reusable
+ pressure rated
Pump and Pressures
depends on injectors, we ran 3 bar, not sure what other people did i think there are some comp rules on low pressure v high pressure systems
Injectors
Throttle Body Injection
basically electornic carb
Port Fuel Injection
Fuel Injected into the ports just before entering the combustion chamber. Usually leads to well mixed charge [citation needed]
Direct Fuel Injection
big boys do this [citation needed]
Fuel Strategy
Efficiency
Consumption vs. Thermal Efficiency
BSFC
- ↑ (2020).Formula SAE Rules 2020(v2.1) Location: FSAEonline. https://www.fsaeonline.com/cdsweb/gen/DocumentResources.aspx.
- ↑ Hillier, V.A.W.; Pittuck, F.W. (1966). "Sub-section 3.2".Fundamentals of Motor Vehicle Technology. London:Hutchinson Educational.ISBN 0 09 110711 3.