What is Fuel: Definition and 579 Discussions

A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but has since also been applied to other sources of heat energy such as nuclear energy (via nuclear fission and nuclear fusion).
The heat energy released by reactions of fuels is converted into mechanical energy via a heat engine. Other times the heat itself is valued for warmth, cooking, or industrial processes, as well as the illumination that comes with combustion. Fuels are also used in the cells of organisms in a process known as cellular respiration, where organic molecules are oxidized to release usable energy. Hydrocarbons and related oxygen-containing molecules are by far the most common source of fuel used by humans, but other substances, including radioactive metals, are also utilized.
Fuels are contrasted with other substances or devices storing potential energy, such as those that directly release electrical energy (such as batteries and capacitors) or mechanical energy (such as flywheels, springs, compressed air, or water in a reservoir).

View More On Wikipedia.org
Recent contents Top users
  1. J

    Gear mechanism and wheel arrangement for reduction of fuel consumption

    Hi everyone, I hope I have posted in the right place. I'm a commerce student and have absolutely no idea about mechanical stuffs. My father has an idea in mind which he would love to implement. He too is a commerce student. Hence, I need some help from you'll to see if this is really practical...
  2. C

    Can you use a Railgun to blast objects into orbit or reduce fuel costs?

    This was an idea I had when when learning about ramjets. I was wondering if you could use a specially designed rail gun to launch a probe or satelitte ,at a very high velocity vertically upwards and then when the object is decelarating at 9.8 m/s due to gravity use a small rocket propulsion...
  3. S

    Is MOX fuel a safer and more sustainable alternative to traditional fuel?

    What are the differences between the use of MOX fuel and "standard" fuel? I've seen mention of the MOX fuel in news reports as being significant, but I've failed to understand their point of mentioning the use of plutonium in the fuel. Are there safety issues? Are there proliferation...
  4. E

    Orbital Shift Hohmann transfer Isp Roket Fuel mass calculation

    1. The launch vehicle takes the moon orbiter to a circular orbit around the Earth at 300km altitude. The orbiter is to perform a Hohmann transfer to a Lunar orbit, entering into a circular lunar orbit at 50km altitude. The objective of the mission is to put a 200kg orbiter around the Moon. The...
  5. C

    Maximizing Distance Traveled with 1200 Joules of Fuel in a Potato Cannon

    Homework Statement We are given an amount perfume, that has an energy level amounting to 1200 joules. Using this as the fuel, i need to build a potato cannon. How can i build the cannon to maximize the distance the potato travels when shot with this amount of fuel? Homework Equations...
  6. M

    Aircraft Fuel Booster Pump - Centrifugal & Immersed in Fuel

    What is the correct way to put limitation on different aircraft flying conditions with respect to the cavitation point of view of the Fuel booster pump in the aircraft? The pump is immersed in the fuel and the fuel tank is vented to atmosphere(in atmospheric pressure, which will change with...
  7. F

    Increase Fuel Mileage: Calculate Torque for 3500 lb Car

    Please help me and calculate the amount of torque required to sustain a car ,3500 lb car medium wind drag. aproxamently 70 mph. I know without wind resistance you can not figure exact but a close estimate would be greatly appreciated. Im wanting to add a secondary mini diesel engine 662 cc...
  8. D

    Can Alloy Wheels Really Improve Fuel Economy?

    Will switching to alloy wheels (typically 17% lighter than steel) noticibly improve fuel economy? It seems like we should be able to calculate a rough estimate if we had necessary data but i don't. Has anyone been there?
  9. F

    How long until molten nuclear fuel at Fukashima cools and solidifies?

    For weeks after the Chernobyl disaster, many tonnes worth of molten "lava-like" nuclear fuel inside Chernobyl's shattered reactor vault eventually cooled down and formed into a hardened substance similar to ceramic. When nuclear fuel overheats and melts, how long does it remain in it's...
  10. baywax

    Is there a way to replace nuclear power with a (big) hydrogen fuel cell

    Could one really big hydrogen fuel cell battery replace a nuclear reactor in providing power to millions of people? This may end up being a safer option for generating power.
  11. X

    Why aren't we using Hydrogen as a source of fuel for cars?

    What I mean by the title is, why isn't it more popular? (I know there DO exist some hydrogen powered cars.) To me it just makes sense to use hydrogen. It is very explosive and it's byproduct is water! The only draw back I can see is storing the gas in the vehicle to be used. Can anyone...
  12. russ_watters

    Fuel Economy Booster: Review of Fuel Doctor Device

    Saw this for sale at Best Buy: http://reviews.bestbuy.com/3545/9754101/fuel-doctor-fuel-efficiency-booster-gray-reviews/reviews.htm The claim is that via power conditioning, the device improves the accuracy of your car's sensors and other electronic devices, thereby improving the car's...
  13. U

    Moderator to fuel ratio and under-moderation in different lattices

    Hi all. I need help on an issue I can't figure out. What is the difference between 15x15 and 17x17 fuel when it comes to moderation properties? Standard fuel with these lattices have dimensions 15x15: pitch: 14.3 mm, d_rod: 10.77 mm 17x17: pitch: 12.6 mm, d_rod: 9.5 mm These geometries...
  14. F

    How can I accurately calculate the cooling effect of an AGR fuel pin?

    Hello and here is my problematic 1st post. I have a problem which i need help with, I'm an electrical engineer so my understanding on this subject is basic. I need to calculate the cooling effect of a AGR fuel pin and I'm not sure were to start. Here is some background on the question...
  15. J

    Spent Nuclear Fuel Pools not dry in 4?

    I am just a finance guy, but I've been reading up on the current crisis and found this blog. Anyone here thing this guy might actually be correct in his assumptions? http://atomicinsights.blogspot.com/2011/03/focus-on-food-water-shelter-dr-greg.html
  16. G

    Question about spent fuel rod cooling pools in Japàn reactor

    Could anyone who actually works on this kind of thing answer a couple of questions about the current situation in Japans nuclear crisis : Is it true that cooling pools for spent fuel rods are stored on the rooves of these reactors ? If so we see two of these rooves have been blown off - so...
  17. A

    Low Air in Tires: Impact on Fuel Efficiency

    Homework Statement Why does a car uses more fuel with lesser air in tyres? Homework Equations Work done =F.d The Attempt at a Solution According to me Friction does no work in rolling if the tyre is purely circular. But when tyes are deflated then they are not circular. Due to...
  18. smokingwheels

    If my car is 56% better on fuel than can I say this?

    If my car goes twice the distance on the same amount of fuel, doing twice the distance the friction and wind resistance is double. Can I say my engine uses fuel 4 times more efficiently? Or is it only double? My thinking behind it comes from Ohms law, if you double the voltage you get 4...
  19. R

    Flight Mach number in terms of fuel flow rate and other parameters

    I've posted on here in relation to an aerospace analysis project I'm doing. I'm stuck on one part of the project where I need to develop the performance envelope of the turbojet engine. 3 of the 9 plots that are required are Thrust vs. Mach number. On each of those plots I'll about 7 different...
  20. S

    Beta or Alpha emitter nuclear fuel cycle?

    Do exist some proposed nuclear fuel cycle in which uranium or thorium whoud be first converted in some beta or alpha emitting isotope and after energy whould be harnessed with direct energy conversion methods?Possibly, it could reduce size of power plant and make steam turbine unnecessary.
  21. M

    How Much Fuel Does a Spacecraft Use to Generate 1.5 MN Thrust?

    A spacecraft ’s motors provide a total thrust of 1.5 MN. If the exhaust speed is 2.5 km/s, at what rate is fuel being used?Homework Statement Thrust = 1.5 MN Exhaust speed = 2.5 km/s rate fuel being used = ?
  22. N

    Increasing Fuel Efficiency through Propeller Upgrades

    Hello, I am looking into ways to increase the fuel efficiency in a various number and type of ships, with engines running from diesels to steam plants to gas turbines. I was wondering where I might find information on the state of the art practices with propeller design. Specifically...
  23. S

    What is Motive Flow in an Aircraft Fuel System?

    Hi, Could someone explain what is a motive flow in the aircraft fuel system? Thanks, Suresh
  24. J

    Rocket fuel efficiency and payload capacity rule of thumb

    "A rule of thumb is that for every ten-percent increase in efficiency for rocket fuel, the payload of the rocket can double.” Can someone assist me with a simple formula to model this rule-of-thumb? What happens to the payload if the rocket fuel efficiency increases twenty to thirty percent?
  25. D

    How to prevent diesel fuel from gelling at low temperatures?

    Low Temperature Diesel Fuel (urgent) I'm having a problem with diesel fuel at the moment and would greatly appreciate insight into the subject. I'm currently stranded in Colorado where it's somewhere like -10 degrees (F) and our diesel truck isn't starting. I've narrowed down the problem to...
  26. E

    Motion of a rocket after all the fuel is exhausted?

    Homework Statement Hello, I am currently a gr 12 high school student, and I am stuck in a problem. Please help :) The problem: Consider the motion of a rocket near the surface of the Earth. In this case, mass, in the form of gas is expelled from the rocket to propel the rocket upwards. A...
  27. T

    Calculating Atom Density of UO2-ThO2 Fuel

    if fuel coposition as follow : 75 wt% Tho2- 25 wt% uo2, were the U enrichment 19.5 w% ... how can i caculate the number density (Atoms/barn-cm) for the comopsition ?
  28. G

    Fuel Consumption of a Ship Traveling at Near Light Speed

    Imagine this scenario: An "airplane" that runs on some type of fuel, let's say, liquid, reaches 90% of the speed of light. Once it achieves this speed, will the ship require less fuel due to time dilation, the same amount of fuel due to time dilation, or more fuel to maintain a constant...
  29. T

    What factors determine the length of fuel cycles in nuclear reactors?

    1- i have a proplem to understand the meaning of the once & twice burned fuel, and why we use when we going to simulate the whole core 2- is there a specific formula for the IFBA radius,
  30. C

    SF Writer in need of assistance - SPACESHIP FUEL

    Hello all - once again! I am an aspiring SF writer currently in the process of writing a book. I am looking for ideas (go nuts!) for different types of spaceship fuels. The idea is that the fuel has to be something that exists in abundance (preferably naturally occurring), and...
  31. A

    Rocket Out of Fuel: Time and Altitude

    Homework Statement A rocket rises vertically, from rest, with an acceleration of 4.0 until it runs out of fuel at an altitude of 1500 . After this point, its acceleration is that of gravity, downward. How long does it take to reach this point? What maximum altitude does the rocket...
  32. C

    Is it Possible to Build a Direct Borohydride Fuel Cell

    Basically as the title says, is it possible to build a DB fuel cell stack? Something that could output 100W (to power a laptop or for power outages). I actually have access to a couple of kilos of sodium borohydride and while looking at what I can do with the stuff I came across this type of...
  33. A

    How can acceleration affect fuel efficiency in a 1991 Geo Metro?

    Greetings everyone! Just a few weeks ago, I got it in my head that I'd like to determine some formulas for the efficiency of an engine - particularly mine, a 1991 Geo Metro. The overall goal is to compare various acceleration rates to show how slower acceleration can produce greater gas...
  34. T

    Volume of a partially full fuel tank

    Homework Statement Finding the volume of a partially full cylindrical tank that lies on it's length. L=6', D=4" Homework Equations pi r sq times L = cu ft when full. Convert to gallons 1 gal. = .1336 cu. ft. (I think) The Attempt at a Solution (pi r sq times L)/2 =...
  35. R

    Is Nuclear Propulsion for Civilian Maritime Vessels a Security Risk?

    Investigate the potential for the use of a nuclear fuel source for aircraft propulsion: If anybody have related document and ideas please post it
  36. DaveC426913

    New-fangled outboard fuel line interlocks

    I've been to Crappy Tire and I've been to Fogh Marine and I ;'ve looked online at Bass Pro. All they have are these new-fangled plastic fuel line/tank interlocks: http://imageserv8.team-logic.com/store-logic/products/5/8680/st_8776.jpg Mine looks like this...
  37. I

    How to calculate fuel to accelerate a vehicle

    Homework Statement Hello, This is not a home work question but as I am not a math or physics major I need some help moving this problem forward. I am trying to calculate how much fuel (petrol/diesel/LPG) it takes to accelerate a vehicle and well to cut a long story sort I seem to be...
  38. I

    How to calculate fuel to accelerate a vehicle

    Hello, I am trying to calculate how much fuel (petrol/diesel/LPG) it takes to accelerate a vehicle and well to cut a long story sort I seem to be getting my units mixed up also whether I should us small or big calories. Lastly is the incline and issue that I also need to consider and how do I...
  39. N

    Find the Time When Rocket Uses Up Its Fuel: Graph Analysis

    A rocket is launched vertically upwards until it uses up its fuel. It then falls back to Earth. Find the time when the rocket uses up its fuel from the graph. My answer was 20s. Is it correct?
  40. S

    Fuel Cells Q&A: Explaining Hydrogen, Electrochemical, & Polymer Cells

    Could somebody expain me the following questions: 1)Why hydrogen fuel cell needs catalyst (such as platinum) to operate, while elcectrochemical elements (such as zinc-air) do not? 2)Why power density increase in fuel cells leads to efficiency decrease while in electrochemical batteries it...
  41. DARKSYDE

    Boosting Your Fuel Efficiency When You Reach C: The Impact of Mass Increase

    when approaching C the mass of your craft increases. If the mass of your fuel increases also wouldn't that mean the faster you go the more fuel youll have?
  42. N

    Optimal Speed for Fuel Efficiency

    hi, what is the exact best speed for fuel economy? why is 5mph less economic than 75mph?
  43. G

    Not understanding how to determine Stoichiometric air to fuel ratio

    Homework Statement Hey, just doing a few problems and i have found i have no understanding of how to solve these types of question, if anyone can help or provide info it would be great thanks... Q " The fuel oil supplied to a boiler contains 86% carbon and 14% hydrogen by mass. Determine...
  44. S

    Could Colloid be the Future of Rocket Fuel?

    Are there any possible performance gains or advantages in a rocket using a colloid as fuel propellant? If so, what might these be, and are there any examples of such rockets having been tried? Solid-fueled rockets are known to offer advantages in higher thrust, while liquid-fueled rockets...
  45. E

    What is environmental impact for mining, processing nuclear fuel?

    The month long debacle over the BP oil spill, and earlier collapse of a coal mine killing scores of coal miners, makes me wonder: what are the risk to human safety and environmental impact for mining, processing nuclear fuel (i.e uranium, thorium) ? Could acquiring nuclear fuel lead to a...
  46. P

    How much nuclear fuel is in a nuclear sub?

    How much fissile material, in kilograms, would, say, an Ohio-class submarine carry? If it's classified, what would be about a good estimate?
  47. O

    Generating Electricity with HHO Gas: What Fuel Cell?

    Is there a way to make the atoms in HHO gas (Browns gas) to separte into it's elements; so the Hydrogen atoms go one way and the Oxygen in another way. By doing this I'm hoping to generate electricity from the reaction by bringing them together again. What kind of fuelcell do I need?
  48. N

    Can I Pursue a Career in Hydrogen Fuel Cells?

    Hi all, I recently made my own hydrogen fuel cell and really enjoyed the process and everything I learned. I didn't know much about electronics or cells, so it was a great learning experience. In my research I found that chemical engineers made a nanometal to work as a catalyst instead of the...
  49. S

    Fuel Cell Efficiency: Average Output for Cars, Homes, & More

    I understand that generating the hydrogen that powers a typical fuel cell is (prohibitively?) energy intensive at this point, but I was curious about the following: Assuming a sufficiently efficient catalyst was obtained that allowed large-scale production of pure hydrogen without...
  50. C

    Fuel Consumed by Oil Refineries

    Hi everyone, I was looking at some data from the Energy Information Association (http://www.eia.doe.gov/emeu/mecs/mecs2006/pdf/Table3_2.pdf\) about the fuel used by different industrial processes. Under the industry of "Petroleum Refining," there is a bit of natural gas and electricity used...
Back
Top