Science

Science entales a wide list of subjects. My environment only touches on a select few: Physics, Chemistry, and Meteorology. In this space, I will cover the subjects of Chemistry and Meteorology; Leaving Physics for the Engineering & Math page.

In my environment, the weather can heavily impact every aspect and ingredient that I have to prepare for success. You may not realize it, but meteorology actually affects everybody's lives in different ways. Temperature and barometer changes can affect your bones and joints, while humidity and precipitation can affect visibility.

To see how this information is used, see the Fuel Control section of the Basic Math page.

Changes in temperature and barometer work together to change the Density of a mass of air. If we reference a pound of air, it will occupy less volume when cooled and more volume when heated. This property works hand-in-hand with Absolute Pressure, which describes how much the atmosphere "weighs". When the atmosphere is Heavy and Dense (Two very different things), there is a very high concentration of oxygen in a given volume of air (such as a cubic foot). When the atmosphere is Light and not Dense, there is a very low concentration of oxygen in a given volume of air.

Many people hear the word "Humidity" on a daily basis. However, did you know that there are TWO types of humidity? The humidity that is commonly referenced by TV meteorologists is Relative Humidity, commonly referred to as a percentage.

The other type of humidity is Absolute Humidity, and is expressed as the number of Grains of Water per Pound of Air. This is a more useful number than Relative Humidity, because it describes an exact enumeration of how wet the air is.

Wind is an important factor to be taken into consider in my environment. While wind speed becomes relevant on a scale of velocity squared, the direction is equally important. A Head wind, tail wind, or cross wind each affect a car differently. A cross-wind is the most difficult to handle, as it can physically push a car around on the track. Head and Tail winds are rather predictable, with head winds being more influential.

In my environment, chemistry is a rather important ingredient to success. In an industry where Fuel, Air, and Spark are all necessary for proper combustion, two of those elements can be chemically explained: Fuel and Air.

As referenced by the Meteorology chapter above, we have three main descriptors of the atmosphere: Temperature, Humidity, and Barometric Pressure. Using these three descriptors, along with a few derivatives (Dew Point, Vapor Pressure, Virtual Pressure, Virtual Temperature), a new atmospheric descriptor can be created: Density Altitude. [Source: Weather.gov]

Density Altitude describes the typical atmospheric altitude of which air of the current density would normally occur, adjusted by the Standard Temperature and Pressure definition. This yields a single number which can be consistently referenced to predict the actual density of a volume of air, and thus, the actual concentration of oxygen within said volume of air.

Stoichiometry is the perfect balance of a chemical equation. In my environment, we combust a fuel to cause an explosion, which moves a piston, producing torque on a crankshaft. Keeping a specific stoichiometric ratio is important for proper combustion, however as the Density Altitude and thus the amount of oxygen in a volume of air changes, the amount of fuel supplied must also change. In our case, we can burn any choice of fuel that we would like, our primary choice is Methanol, with select additives.

Equations below neglect the various other gasses in the atmosphere, and rely only on the basic formula of combustion. As such, they are not necessarily true in the "real world", and used for illustration purposes only.

Methanol: 2 CH3OH(l) + 3 O2(g) → 2 CO2(g) + 4 H2O(g)

Two atoms of Carbon, Eight atoms of Hydrogen, Eight atoms of Oxygen.

Methanol + Nitromethane: 2 CH3OH(l) + 2 CH3NO2(l) + 4 O2(g) → 4 CO2(g) + 6 H2O(g) + H2(g) + N2(g)

Four atoms of Carbon, Fourteen atoms of Hydrogen, Fourteen atoms of Oxygen, Two atoms of Nitrogen. If standardized to the available amount of air, for comparison to Methanol alone:

(3/4) 2CH3OH(l) + (3/4) 2CH3NO2(l) + (3/4) 4O2(g) → (3/4) 4CO2(g) + (3/4) 6H2O(g) + (3/4) H2(g) + (3/4) N2(g)

(1.5)CH3OH(l) + (1.5)CH3NO2(l) + (3)O2(g) → (3)CO2(g) + (4.5)H2O(g) + (3/4) H2(g) + (3/4) N2(g)

In total, 150% of fuel is able to be burned for the same amount of oxygen (1.5 units of Methanol + 1.5 units of Nitromethane, versus 2 units of Methanol alone). As a result, more power is produced. This is assuming that the fuel is exactly 50% Methanol and 50% Nitromethane.

Methanol + Nitrous Oxide: 2 CH3OH(l) + 2 N2O(g) + 2 O2(g) → 2 CO2(g) + 4 H2O(g) + 2 N2(g)

Two atoms of Carbon, Eight atoms of Hydrogen, Eight atoms of Oxygen, 4 atoms of Nitrogen. If standardized to the available amount of air, for comparison to Methanol alone:

(1.5) 2CH3OH(l) + (1.5) 2N2O(g) + (1.5) 2O2(g) → (1.5) 2CO2(g) + (1.5) 4H2O(g) + (1.5) 2N2(g)

(3)CH3OH(l) + (3)N2O(g) + (3)O2(g) → (3)CO2(g) + (6)H2O(g) + (3)N2(g)

In total, 300% of fuel is able to be burned for the same amount of oxygen (3 units of Methanol + 3 units of Nitrous Oxide, versus 2 units of Methanol alone). As a result, significantly more power is produced.

Compressed Air: (also known as boost)

This method is more difficult to evaluate. With the induction system pressurized to 39.7 pounds per square inch absolute, we have exceeded natural pressure (14.7 psia) by 2.7 times.

Methanol at 14.7 psia: 2 CH3OH(l) + 3 O2(g) → 2 CO2(g) + 4 H2O(g)

Methanol at 39.7 psia: 5.4 CH3OH(l) + 8.1 O2(g) → 5.4 CO2(g) + 10.8 H2O(g)

5.4 atoms of Carbon, 21.6 atoms of Hydrogen, 16.2 atoms of Oxygen

In total, 270% of fuel is able to be burned for the same amount of oxygen (5.4 units of Methanol versus 2 units). As a result, significantly more power is produced.

The benefit to running a boost setup is that there are no explosive/dangerous chemicals involved, while being able to make power comparable to a nitrous-assisted combination. The more air that you can compress, the more fuel you can send with it, to make significantly more power.

TOP FUEL:

Top Fuel is what you see on TV. They run greater than 84 psia of boost on a fuel that is 85% nitromethane to make over 11,000 horsepower.

Methanol + Nitromethane (15/85 Mix):

0.5 CH3OH(l) + 3 CH3NO2(l) + 3 O2(g) → 3.5 CO2(g) + 5.5 H2O(g) + 1.5 N2(g)

Note that for the same 3 units of air, we have gone from 2 units of fuel to 3.5 units of fuel.....

Now, Add in 5.76 times more oxygen.....

2.8 CH3OH(l) + 17.3 CH3NO2(l) + 17.3 O2(g) → 20.2 CO2(g) + 31.9 H2O(g) + 8.6 N2(g)

And this is why Top Fuel is usually seen on fire.... That is A LOT of fuel. How much, in fact?