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Old 07-02-2006   #221 (permalink)
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Re: the jet propulsion with closed combustion type

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Old 07-05-2006   #222 (permalink)
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Re: the jet propulsion with closed combustion type

There are many ways to ignite the mixture gas in the chambers. Each of them has weakness and advantage. Such as, the energy to ignite is small; the flame isn’t stable; the heat load is big…
I always think of if there is a good solution for ignition, which has simple structure, is easy to realize, has enough energy to ignite the fresh gas, has as low as possible heat load to the components. Recently I have a idea: the igniter is in a cavity installed the front door. Inside the resistance wire is heated by electricity continuously or intermittently to rather high temperature. The cavity has two openings, one is open to the enter pipe, when the fresh gas come in the cavity, it will be ignited and with flame. When the position of cavity turn to a chamber with the front door, through another opening of the cavity and by the gas pressure the flame in the cavity will enter the chamber that just finish entering fresh gas, so the fresh gas in chamber begin to burn if they have proper parameters. When the cavity moves away the chamber, the pressure in chamber rise rapidly. By the fresh gas flow through the cavity by two opening, the gas can cool the component around the cavity. When we want ignite the gas in cavity, we just left the opening to enter pipe open, close another opening.

The front door separate the fresh mixture gas in inlet pipes and the fresh gas in chambers, We can take advantage of it. so we made modification inside the front door. the front door is rotating, it can suck the high pressure air from the blow/compressor then add pressure, there are small slots or small holes at the edge of opening of the front door. When the front door close the chambers. the clear air run out through the slots or holes and stop there, These clear air separate the fresh mixture gas to the front door, it protects the front door from burning. It also has function of safety about fresh mixture gas in the inlet pipes.

Last edited by qumf; 02-28-2007 at 02:14 AM..
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Old 07-07-2006   #223 (permalink)
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Re: the jet propulsion with closed combustion type

Sorry to go M.I.A. on you again.....soooooooooooooooo tired.....so very very tired..............I desparately need a vacation!...........

Engine scrap!!!!
Starting over!
AAAAAAaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrgggg!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
New design no "borrowed componanents" (salvaged)
no valves , no gates, no f#cking central hub, no f#cking compressor !!!!!!!!!!!!!!!!!!!! IT will be MAGNIFICENT!!!! IT will be BEAUTIFUL!!!!
IT will be the most efficient f#cking turbine engine ever dreamed of!!!!

news soon!


----------------
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Old 07-08-2006   #224 (permalink)
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Re: the jet propulsion with closed combustion type

Quote:
Originally Posted by DFINITLYDISTRUBD
Sorry to go M.I.A. on you again.....soooooooooooooooo tired.....so very very tired..............I desparately need a vacation!...........

Engine scrap!!!!
Starting over!
AAAAAAaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrgggg!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
New design no "borrowed componanents" (salvaged)
no valves , no gates, no f#cking central hub, no f#cking compressor !!!!!!!!!!!!!!!!!!!! IT will be MAGNIFICENT!!!! IT will be BEAUTIFUL!!!!
IT will be the most efficient f#cking turbine engine ever dreamed of!!!!

news soon!
Your safety is first.
I can't image there is such a good engine.Can you desdribe roughly it to me?draw a draft.
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Old 07-14-2006   #225 (permalink)
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Re: the jet propulsion with closed combustion type

DFINITLYDISTRUBD

You originally thought the engine too simple, it isn’t appropriate; you just consider the structure of the engine, you simplify the structure further. I guess you don’t understand the work principle at the base. You develop it by your experience and imagine. So you failed. During the course I remind you many times.
I try to analyze the reason you failed: you just use a chamber, and the shape inside chamber is simple. The combustion and the flow of the gas exit at the same time. You didn’t control the flow speed and position of flow well either. I think it is hard to keep the flame steady. The fire is blown down.
On another side, the composition of gas near the flame is also important. You didn't control well either.

So far I still think, depending on your material by great effort to get, you fabricate some necessary parts also, it is compeletely you can succeed.
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Old 07-27-2006   #226 (permalink)
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compare two type engines' actual efficiency

The principle is easy to understand, though the theoretical efficiency of the two types of jet engines are close, the compressor in the current engine consume a lot of (over half) energy from the burnt gas, further the compressor's efficiency is low. So the new type engine's actual efficiency is higher than the current .


Before I estimated the new type engine's actual efficiency, but I describe too roughly. Now I sort these material and release, I hope somebody can point out the mistake if there is. (Though the case is estimated, I still think it is representative and persuasive)
Firstly I state some premises:
1. The data I chose for the example are not the most advanced, but representative

2. The data is from jet engine, not from turbo-generator. Though their structures are similar, the data are different because they work under different conditions with different requirement.
3. In below analyse I assume that the portion's efficiencies are same if two types engines have the similar function component.
Below I state the example with data to explain.I think it real hard to describe the all main charateristics' relation and variation only with formulations about each course. maybe impossible.

As to the current jet(combustion under constant pressure, there is a theoretical formula. η=1-1/W^[(k-1)/k]
W is in crease rate of compression, in the example I set: W=10,k=1.4, the theoretical efficiency of the current jet is 48.2%.
As to the new type jet engine( close combustion), the efficiency formula: η=1-k*[U^(1/k)-1]/{ W^[(k-1)/k]*(U-1)} You can see the demonstrate course from previous post.
U is the in crease rate of pressure by combustion, here U=8, W is increase rate of gas pressure by blower. W=3 here
I input the data, you can see the theoretical efficiency of this closed combustion jet engine is 50%

By knowledge of Thermodynamics, if without cooling during compression, comparing the energy of compression the gas from 1bar to 10 bar with from 1 bar to 3 bar, the rate is 2.524 times.
By some published material, under common condition, I assume the actual efficiency is 80% for a compressor with compression rate=3. I compare the compression rate 3 and 10. The blower and compressor operate the gas by a stage after a stage. Thus I estimate the actual efficiency of a compressor with compression rate=10 is 65%.(Note: the efficiencies is for whole course, from suck air from atmosphere to completion compression.)
As to current jet engine, by a common case, 55% energy that can be utilizes from burnt gas is given turbine.(the proportion is higher in some jet engines). I also assume the actual efficiency of turbine is 100%
the actual efficiency is: η=(W1-W2)/Q W1:the energy can be utilized from the gas after combustion, W2: the energy the turbine consumes; Q: the chemical energy that the fuel contain.

So η=(W1-W2)/Q=[(W2/0.55)-W2]/Q=0.818W2/Q

The theoretical efficiency: η1=(W1-w2)/Q w2: the consumed energy by turbine theoretically, before I calculated the theoretical efficiency of jet engine, the efficiency of compressor is assumed 100%. the turbine transfer the energy to compressor, the energy consumed by compressor theoretically is less than actual consumed, so the energy consumed by turbine theoretically is less than actual consumed. The rate of the theoretical to the actual is 65% that is the efficiency of the compressor.

So η1=(W1-w2)/Q=[(W2/0.55)-0.65W2]/Q=1.168W2/Q

η/η1=0.70

As to the new type jet engine I proposed, what proportion of whole energy consumed by the turbine that is from the gas after combustion?
55% energy that can be utilizes from burnt gas is given turbine in the current engine, from previous explanation, comparing the energy of compression the gas from 1bar to 10 bar with from 1 bar to 3 bar, the rate is 2.524 times.
Thus after combustion, about 55%/2.524=21.8% energy is consumed by turbine. the course should be thought over . We can understand as below:

We assume that the two types of the engines have the energy on the gas after combustion, by previous analyses, their theoretical efficiency are similar, one is 50%, another is 47.4%. The gas after combustion works, there are two aspects, a portion is to drive turbine, and others is to accelerate the gas itself. 55% is theoretical data, 2.524 times is rather accurate data by calculation, or it has some margin. The last data 21.8% can be actual data.
The actual efficiency for the new type engine is: η=(W1-W2)/Q W1:the energy can be utilized from the gas after combustion that can be utilized; W2: the energy the turbine consumes, Q: the chemical energy that the fuel contain before combustion.
So; η=(W1-W2)/Q=[(W2/0.218)-W2]/Q=3.587W2/Q

The theoretical efficiency is: η1=(W1-w2)/Q w2: the consumed energy by turbine theoretically

When I analyzed theoretical efficiency of the jet engine, I assume the efficiency of blower is 100%, the theoretical energy consumed by the turbine is less than the actual. The rate of the theoretical to actual about the turbine is 80% that is same as the efficiency of blower.
So η1=(W1-w2)/Q=[(W2/0.219)-0.8W2]/Q=3.787W2/Q

η/η1=0.947


I put 48.2% as the theoretical efficiency of the current jet engine into the formula, We can get the actual efficiency 34%
I put 50% as the theoretical efficiency of the new type engine into the formula, I get the actual efficiency 47.35%
To compare the data, the actual efficiency of the new type engine is higher than the current by 39%


It is very pleasant that the efficiency can higher so much, but it is theoretical. I think it is enough if the efficiency can be higher 30% actually.
As to the current engine, the best theoretical efficiency may better than I said. Some parameters may not match well each other, but I think the deviation is small and it can be neglected in this example.


As to the new type engine(closed combustion type), some energy will waste when the gas runs from the branches pipes to general pipe.
I conclude that a little energy be wasted while the gases converge together from the branch pipes because below:
1). The convergence occurs in a small closed space.
2. Before convergence main currents have same speed as well as same direction. During and after convergence there is a proper space and necessary for the course. 3) some small currents join the convergence, but their mass are small and their condition are not harmful to others.


Somebody may think, the actual efficiency of the current jet isn't as high as I state here, It is because the jet must work under a wide range condition, Some parameters aren't operate under best data that can cause the better efficiency. Some waste is ignored.
Really I deal with some course too simply, But I think it won't influenced the conclusion.

Last edited by qumf; 01-13-2007 at 02:21 AM..
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Old 08-08-2006   #227 (permalink)
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Re: compare two type engines' actual efficiency

HI!

Can you say eurika!!!!!!!!1

Preliminary #'s are lookin reeeeeeeeeeeeal good!

113.lbs
97cc total combustion chamber displacement.
300 and change ft/lbs torque @ 17850 rpm.
max. rpm. somewhere in the neighborhood of 75 or 80,000 rpm. (dont want to push it too hard yet.)
fuel consumption - 1 gph @ 45,000 rpm.
Thrust- enough to accellerate my 4,900lb pick-up truck from 0 to 110mph in 11 sec. (if you want actual #'s you'll have to do the math!)


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Old 08-10-2006   #228 (permalink)
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Re: the jet propulsion with closed combustion type

DFINITLYDISTRUBD :

I have some questions because you don’t state it clearly.
1. Is the “113.lbs” the weight of your engine?
Is the “4,900lb” the weight of truck?
2. Is your engine a jet engine or internal combustion engine, why it has the torque “300 and change ft/lbs” if it is jet engine?
3. How many chambers do you adopt? Do you use only one chamber?
4. How do you control the chamber’s opening and closing? Do you use rotary valves as before.
5. I am not clear the specification of common internal combustion engine. I am sure you have a lot information on this field. You can compare it with others.

I also will calculate “ push force/engine weight
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Old 08-19-2006   #229 (permalink)
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Re: the jet propulsion with closed combustion type

Annotation:

Regarding the explain below why the actual efficiency of the new type jet engine is higher than the current one, I should correct one sentence:

As to current jet engine, by a common case, 55% energy that can be utilizes from burnt gas is given turbine.(the proportion is higher in some jet engines). I also assume the actual efficiency of turbine is 100%

should be ......55% energy that can be utilized by meanings of the expansion of the gas from burnt gas......I also assume the actual efficiency of turbine is 100% that is based on the difference of the gas's energy before and over the turbine.
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Old 08-19-2006   #230 (permalink)
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Re: the jet propulsion with closed combustion type

reply#229 is for #226
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