Combustion Definition and 363 Threads

Why does combustion emit light? For heat, for excited electrons or for other reasons?

Greetings All! I am not sure if this is the correct place to post this, but I think that since rocket fuel is considered a chemical reaction, this sections seems appropriate. Right, to the topic. Me and my team from the spaceflight society are looking forward to building a hybrid rocket fuelled...

In combustion science, typical flames that are studied are premixed or diffusion flames, where a stream of methane, propane or some other fuel is released to an atmosphere of air or oxygen and ignited. Another scenario is a "pool fire", where a puddle of volatile solvent is burning in air and...

Homework Statement A 2.56g sample of anthracene, C14H10, was burned to heat an aluminum calorimeter (mass=945 g). The calorimeter contained 1.50 L of water with an initial temperature of 20.5 C and a final temperature of 34.3 C. a) Calculate the molar heat of combustion of anthracene...

Hi, I'm a high school chemistry teacher trying to develop a lab experience demonstrating combustion analysis. This is usually something we go through theoretically during discussion of percent composition and empirical formula. I'd like to actually perform one. I was wondering if this could...

Homework Statement [/B] A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume. It is to be fed to the combustion chamber in 10% excess air at 25°C, where it is completely burnt to carbon dioxide and water. The flue gases produced are to be used to...

Homework Statement The combustion of 0.1577 g benzoic acid increases the temperature of a bomb calorimeter by 2.51°C. a) Calculate the heat capacity of this calorimeter. (The energy released by combustion of benzoic acid is 26.42 kJ/g.) A 0.2123-g sample of vanillin is then burned in the same...

Homework Statement A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume.It is to be fed to the combustion chamber in 10% excess air at 25oC, where it is completely burnt to carbon dioxide and water. The flue gases produced are to be used to generate 5...

Homework Statement [/B] Im trying to find the efficiency of a gasoline engine regarded as a control volume. Am I right to use the HV as total energy input into the system? Assuming the enthalpy of formation of the fuel can't be found. I am really wondering if enthalpy of formation equals the...

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On average, which has higher power to weight ratio between the two? So on average, if both weighed the same, which one is going to have more power?

I was analyzing the Lamborghini Aventador's tech. specs. and it is given Bore x Stroke 95mm x 76.4mm and compression ratio 11.8:1. Then I calculated the volume of displacement and it's 541.5 cm^3 for each cylinder. Then I know the compression ratio as $$\frac{V_1 + V_2}{V_2} = C.R$$ $$...

Homework Statement Toluene, C7H8, is burned with 30% excess air. A bad burner cause 15% of the carbon to form soot (pure C) deposited on the walls of the furnace, what is the Orsat analysis of the gases leaving the furnace?Homework Equations C7H8 + 9 O2 => 7 CO2 + 4 H2O 30% excess of air What...

A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume. It is to be fed to the combustion chamber in 10% excess air at 25ºC, where it is completely burnt to carbon dioxide and water. The flue gases produced are to be used to generate 5 bar steam from water...

The enthalpies of formation with reference to (2) are: ∆(Glucose)= −1,268 /, ∆(Carbon Dioxide)= −393.5 ./, ∆(water)= −285.8 /. How do I calculate the enthalpy for the combustion of 1 mole of glucose? I know H = U + PV and ∆H = Q + Wother, but I am confused by all the chemistry involved!

Hi all, I am currently considering a heat transfer problem. In this problem a rectangular vessel made of stainless steel is heated by a surrounding jacket with hot combustion flue gases flowing through it. This means that the heating of the rectangular vessel is achieved primarily through...

Hi there, I have a problem that I cannot find a solution too. In this problem I have a fuel (approximately natural gas) supply which is combusted when mixed with air inside a burner. The flame that is then generated is used to heat up a sealed cylindrical vessel (the flame is on the outside of...

What is the meaning of the appearance of the following species in a combustion: -OH -H2O2

Just out of curiosity, as I am very amateur here, in ICE could mono-crystal Alumina replace aluminum and create a better engine? Aside from the high cost to manufacture. I know MC-Alumina has a higher density than Al but is considerably stronger. This would be fantastic, I would think for a...

Hello chemists, need some help here. I'm trying to calculate the power output of a certain otto cycle using different fuels, specifically gasoline, ethanol and different combinations of the two like 85% ethanol and 15% gasoline or 50% ethanol and 50% gasoline. However I have found it difficult...

Hi guys, 42 year old engine hobbyist here, not a student. I've had great luck figuring out my questions in this portion of the forum in the past and look forward to your input. Keep in mind that I'm not formally educated, so if it's possible to dumb something down a bit I'd appreciate it.1...

Homework Statement : [/B]At the beginning of the compression stroke of a two-cylinder internal combustion engine the air is at a pressure of 101.325 kPa. Compression redeuces the volume to 1/5 of its original volume, and the law of compression is given by PV^1.2 = const. If the bore and stroke...

I have been trying to determine the efficiency of an ideal Otto cycle based on the compression ratio of my car and the heat of combustion of gasoline and I think I'm not entierly wrong but there is something quite off. When trying to calculate the temperature of the combustion stage my result...

Im working on a problem regarding a SSME and need to figure out the balanced eq for LH2 and LOx. I thought it was simply.. H2 +0.5O2 > H2O however my professor has confirmed that it is not the case in this situation. I am stumped as to what it could possibly be, maybe excess H2? And am not...

Homework Statement A 1.250 g sample of ##C_8H_18## is burnt with excess oxygen in a bomb calorimeter. Change in temperature is from 294.05 K to 300.78 K. If heat capacity of the calorimeter is 8.93 kJ/K. Find the heat transferred to the calorimeter. Also calculate the enthalpy of combustion of...

Homework Statement Hi , I'm struggling with new paragraph about internal engines. When four-stroke internal combustion engine spins crankshaft 100 times , piston does 300 ticks. How many cilinders does engine has? Homework Equations I don't know how to create equation to calculate that , i...

Homework Statement The heat of combustion of graphite and that of CO is 394kJ/mol and 283 kJ/mol, respectively. When 12g of graphite is combusted incompletely, the same volume of CO and CO2 are generated. Calculate the heat of generated by this combustion. Choose the closet value.(kJ) A.197...

Hello members, I wish to produce and "store" "Methane" gas. I wish to accomplish this task by conducting out a reaction between carbon-dioxide an water. I have my own source of energy and I completely understand that the reaction is endothermic. The reaction is: CO2 + 2H2O + energy = CH4 + 2O2...

Dear engineering community: For many years now I have wondered why our internal combustion engines have not been adapted for methane in place of the various forms of petroleum products we currently use. Why? (1) Because we have a gargantuan ever-renewing source of methane in human garbage...

With so many advances in technology and science, I find it difficult to believe that no one has cracked the code on non-flammable 'fireworks'-- something that still gives us the same bang for our buck without the ash and firestarters falling back to the earth. So, here's a challenge: Present an...

I've read a bit about fire on wiki and I have some questions. 1. There is an exact ignition temperature for each material. Temperature reflects the amount of energy, heat. But also specific heat capacity of a each substance is different. So is the amount of heat, which is necessary for of...

Homework Statement I'm currently doing a grade 11 chemistry lab online...So, there's three reactions that we have to interpret... 1. CH4 + 2 O2 ---> CO2 + 2 H2O 2. 2 C2H6 + 7 O2 ---> 4 CO2 + 6 H2O 3. C3H8 + 5 O2 ---> 3 CO2 + 4 H2O Now, when I add the theoretical masses of the products for...

Hey guys, I'm trying to write a small article that very simply explains some of the math involved with a rocket engine. I'm not looking for a very accurate answer so I tried the following method 1) Stoichiometry on the fuel which was sugar and saltpeter and their respective enthalpies of...

how much pressure can be generated upon ignition of gasoline/air in an internal chamber at atmospheric pressure? I know that combustion engines can generate well over 1000 psi on the piston but this occurs when the air is compressed to begin with.

Hi, I am trying to model a counter flow diffusion flame using ansys fluent with fuel/oxidiser as methane/air. The problem is that the flame temperature(800 K) is much lower than what it should be(>1600 K). I am using Non premixed combustion module with steady diffusion flamelet and adiabatic...

Hello, I was curious about how to calculate how fast the escape velocity of hydrogen out of a tube/cylinder would be. Once end of the cylinder is closed, the other is open, obviously. Assume the cylinder is full of hydrogen at 1 atm. My thought is that you could use PV=NRT to calculate the...

Hi there, I was wondering if you could kindly help me in one of the question. its a tiny question.. the question is 1. A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume. It is to be fed to the combustion chamber in 10% excess air at 25ºC, where it is...

Hello all! I am going out on a limb here looking for information as I am unable to find the answers scouring the internet. Essentially I want to know how a person would go about getting a job working with Gas Turbine Tuning and Controls? I've got an engineering background, lots of gas turbine...

< Mentor Note -- Poster has been reminded to use the Homework Help Template and show their work on schoolwork problems > Hello everyone I have some questions on engine calculations that I need help in please. 1) A reciprocating internal combustion engine operates on a 4 stroke cycle. If the...

Once upon a time I managed (unintentionally) to use a primitive centrifuge to spin a jet of steam. The spinning steam jet separated (or more likely partially separated) into hydrogen and oxygen components. A blue flame appeared at the confluence of gasses. I do believe that steam had partial...

Internal engines got a flywheel connected to the crankshaft on one side, and on the other there is a wheel that drive all the engine accessories with a belt. If the main power output would be taken from the "belt" wheel and not the flywheel, would I receive the same power output? And if no, is...

Homework Statement The combustion of hydrazine, N2H4, produces nitrogen gas and water vapor. The heat of combustion for this reaction is -618 kJ/mol. If 1.6 g of hydrazine are combusted in a bomb calorimeter at 298 K and with a heat capacity of 6.2 kJ/C, what will be the temperature of the...

Homework Statement one gram of each of the following gases is introduced into a 10 L container at 25 degrees C a) propane b) ethane c) methane d) pentane which gas will consume the greatest mass of oxygen upon complete combustion? The solutions says that the right answer is D. I do not know...

hi i have a cylinder whose volume, intake and exhaust area is known. i know the amount of air entering into the combustion chamber(cylinder) and the amount of fuel entering into the combustion chamber. i am taking an ideal approach and assuming stoichiometric combustion (LPG). is there any...

Hi, working on a project and I need some assistance due to my lack of education in mechanical engineering. With that said I will be as specific as possible. I need to figure out how much PSI is exerted on a piston during the power stroke in an external combustion emgine. I'm not sure how to...

Hello I am teaching physical science at an online school, and came across this issue in the textbook - I'm looking to double check with more knowledgeable people before I bring it up and potentially make a fool of myself. In one chapter of the physical science text it discusses various...

I have always had a fascination with trying to come up with new and unique, and (possibly) practical ways to increase the warm weather output capacity of combustion turbines. Any help or suggestions for possible options would be appreciated. In warm weather the density of the ambient air drops...

Noticed that when u burn something its mass decreased like if u place a fuse on a scale and burn it, its mass decreases. But Antoine Lavoiser determined that if all the particles in the gas collected, like if you burn the fuse inside a closed bottle the mass stays the same...i don't understand...

Hello everyone I got diesel engine, and there is a backpressure applied in the exhaust. I know that when the exhaust pressure reaches approximately 6 atm. the engine stalls. The question is, how I'm able to calculate this precisely, especially when the backpressure didn't reach it's maximum...

I want to model the diffusion-controlled combustion of a small carbon particle. The system I want to model is similar to this one However, I'm not going to use the stagnant gas film model as shown in the figure, since I lack data for the film thickness, and I want to evaluate the problem...