qumffrom the little I know and I have seen in your drawings (I may well be wrong), there is -in my mind- a significant likelihood of vibration. Lots of it.
I am not criticizing or anything. I am just having a thought here.
what you worry has some kind of reason, I do my best to avoid, such as all moving parts are rotating, many pairs work cooperaye, noy only one pair, I set some parts or space as buffer cache, to reduce the size of wave,
qumfYou know that Rolls Rocye has made similar work and patented this?
http://www.patent-de.com/20080417/DE19600679B4.htmlSimilar work NASA-Report Nr. TM X-71906 „Preliminary Evaluation of a Turbine/Rotarg Combustion Compound Engine for a Subsonic Transport”
i can not open the website( you link), can you copy and send it to my mailbox? [email]qumf@163.com[/email]
qumfmaurobaggio, Thank you for your comprehension.
my target is to utilize the advantage of the type combustion, even to develop the new advantage. meanwhile to avoid the disadvantage.
the type combustion is very easy to lead to Pulse jet engines , my idea is: by means of modifying the structure, the whole pulse force and mechanical power output are constant basically.
qumfi correct a mistake in the second floor to avoid confusion.
qumfWhat you just described is a pulse detonation engine.
By what you said, I only can say they have the same charater.
qumf@jetman-2
But this has in it’s core a pulse detonation engine, all he added was a compressor to force air in. …..: http://www.pulse-jets.com/valveless/
in my design , the motivition of the gas flow into the chambers, depend on not only the compressor but also suck effect caused by the high speed gas flow out off the chambers. the later one is bigger.
qumfThose doors are a great way to stall the compressor. You will get an un-even flow thru the compressor, since at any instant some sectors are blocked. It simply will not work. It is difficult enough to have a smooth flow at all flight conditions, engine controls took decades ……
I suggest you read the article again, especially the last section of “Feasibility and improvement solution“
Later I change the way of input gas, the gas flow with a little rotating in front of the chambers. I realize it by a pair of short rotating branch intakes. only through the pipes the input gas can meet the chambers. Thus the input gas pressure doesn’t change so much. and the pressure variety has less influence on input gas than previous one.
qumfI have no problem with your concept, generally, it is good, but seems too many aspects unclear with those you called detail. Why don’t you ask NASA and go to see what they will say? I still put suspicions on that door, it is key here for me.
yes, to design the doors is comparative difficult, they are very import parts and complicted parts. You should consider many aspects: firstly seal function, here I adopt plain surface seal type, then it should be light and simple structure as possible as i can. It can bear high temperature, for the front door we should consider input gas for small flow resistance and ignition function , gas pressure balance and so on…
How can contact NASA? Can you give me their contact information?
I ever consulted a few Chinese institutions or relative person like NASA in USA for opinion, one had no comment, one refused to read, two gave some opinion like the comments here, no any special conclusion which is out off my expection.
I can understand, they have their own thing to do.
Who can tell tell me how to put Drawing pins on the topic (stick the discussion)as the upper threads?
qumfThank everybody, I am so happy that many friends attend the discuss.
to Amiga500, i think what you said basically are right. many people are trying the way to inmprove that you mentioned ,i just try from another way.
to JT442, i try to increae the rotation speed of the front door and rear door, (ie. increase the frequency of work) because the time spent on combustion is tiny little each time.
two doors are heavy, but the compressor at high portion is still heavy. i agree to compare their weight is hard right now.
The input course in my first explanation is kind of what you said, it would be influence the input gas flow Seriously, at last I change the way of input gas, I adopt the rotation way to input gas, thus there are very short branch pipes in front of the chambers and the pipes are rotating. The input resistance will be decrease a lot.
“you have turned the gas turbine into a pulse jet engine” ,Yes it is like some extent, but it is different from anything people have made.
to emile , to discuss the shape of the front door and rear door is matter of detail, i think it is early and unconvient for here.
I did not say i would abolish the compressor, pls read carefully,especially from the working circle figures you can get the my idea.
because the high speed of gas, the rotation speed of blades and doors are too different , so I use transmission or pnematic way the control doors rotation. and the shape of chambers are like cylinders
qumfThank everyone.
to MadRat, I hope while the gas flow very quickly through blower or compressor, the gas hit the fuel, the fuel is from blade, (static blade or ..), because the speed of air is vey high, the fuel can became very little particles. so the fuel can into air, they mix.
I referred many books in the field, I consult the internal combustion engine and curent jet engine : how do they scatter the fuel into air. I think it is feasible.
to matt, i have studied all main relative books in this field. i think it is feasible. i think I need not consult the professors, if they say no, you don’t agree, will you stop it? if they say yes, do you think they will help you in China? I also consulted some specialist, one of my relative is real specialist in jet engine.
These books i have read are all chinese, I can not translate the information of the books into English and list here, for me it is hard.
to matt, for me, it is possible to build a model, It is nor very hard. but because my capability, It can not get high efficiency, if it is low efficiency, I can not persuade others to accept my engine.
to schurem,Erkokite,over G, I thank you again, I will consider your comment carefully,
for the cuurent jet Engine, the gas speed is not always very high inside. while the gas burning in the chamber, the speed is low, otherwise the flame is put down.the combustion can not continue.
for other technic issues, i can not persuade you now. only after the engine success, it can tell us the truth.
At last I hope you can provide me other proper web site to introduce my proposal.
qumfSomebody ever reminded me, the constant-volume combustion type turbo-generator was proposed, and realized many years ago. (In a sense the constant-volume combustion is same to closed combustion)It has much weakness: the structure is too complicated, the efficiency is low. So it is replaced by constant-pressure combustion type later. (They think my engine is same to the constant-volume combustion type engine).
I replied to the query, though I call it “the closed combustion type..” my engine has different structure from those constant-volume combustion types engines definitely; meanwhile I always attempt to adopt the simplest mechanical action to realize the functions; If people who have learned the theory of combustion read the principle of my engine, they will know the combustion in my engine is not a common constant-volume combustion concept. Because the pressure and temperature rise to very high level rapidly in the combustion, the spread speed of blaze is very high; it is sonic or supersonic speed. Since the combustion spends little time, we needn’t keep the doors of chambers closed until the combustion finish entirely. The solution is also very good for chambers to bear the varied forces. Thus the topic of the article seems not so accurate.
In recent years, in the world the fuel is always in short supply. So to study the efficiency is important. Meanwhile the level of manufacture and development new material improves quickly than before. It is more feasible and easier to realize the new jet than before. Another aspect, due to increasing carbon dioxide in atmosphere, globe warming become a big problem concerns everybody. I hope applying the new type of engine will slack up the trend.
qumfAs to ignite the gas in chambers, I have three ideas. Each of them has weakness and advantage.
1. to install some instrument inside the chambers, ignite the gas at proper occasion.
2. to ignite the mixture gas at proper occasion by the burning gas from the previous chamber through the front door.
3. to ignite the fresh mixture gas by the burned gas in the same chamber at the beginning of the fresh gas entering the chambers. I think it is feasible at a certain frequency and proper original pressure.
Recently I have solution for idea 2: It is easy to realize, has enough energy to ignite the fresh gas, with small heat load to the components. The igniter is installed with the front door. Inside it the resistance wire is heated by electricity continuously or intermittently to get high temperature. A cavity inside the front door has two openings that can connect two chambers nearby at certain position. The fresh gas is ignited with flame in most case. When the front door turns to the position , through an opening of the cavity and by the gas pressure the flame will enter the chamber that just finish entering fresh gas, so the fresh gas in chamber begin to burn if they have proper condition.
In this new type of engine the seal is harder than the current engine, but I think it won’t be very difficult. The seal in several places are by the flat surfaces, not a line. Personally I think the importance is to control the distance between two surfaces. Another aspect the extreme high pressure during these courses exist very short time. The flat surface is good to adopt a devise to control the gap of seal to get the good seal function.
In very thin tube or little gap the flame spreads much slower than it in normal space. The principle can be adopted in seal. The burnt gas with high pressure can also be filled in gap of seal to separate the flame, prevent the flame spreading inside.
The function of branch pipes behind the chambers:
When the burnt gases enter the turbine, keep their speed and pressure stable is important. It’s good for efficiency and bearing load. It also can be realized. The initial condition just after combustion is same. By the branch pipes and a short time the gas from a pair of chambers has comparatively stable pressure and speed. Base on the feature, several pairs of chambers spout gas alternately and cooperate, we also can add a space behind branch pipes as buffer storage and to regulate gas before turbine, when the gas encounters the turbine, the condition is relatively stable.
Here we can see the function of branch pipes:
1. As buffer storage while the gas rush out off the chambers, to reduce the fluctuation.
2. The gas can flow in it even though the pressure in chambers isn’t so high.
3. without the branch pipes, when a branch pipes spouts gas, the current will influence the sweeping gas from the branch pipes nearby. Installing the branch pipes; the course will help each other by the effect of suction.
A reader reminded me that the gas will lost a little energy when it runs from the branch pipes into general pipe due to the gases with different conditions from different pipes encounter. —I admit.
It is hard to estimate that how much energy loss. What I can do is to analyze this waste’s principle. I designed the branch pipes that make the gas in general pipe more stable than without the branch pipes. It has the effect of buffer storage that reduces the change of the gas condition because the gas’s spouting is similar to impulse. 2. Fortunately the amount of gas from sweeping course (or the gas similar to the course) is much less than the amount of gas from the spouting course, so the loss is small. We also need to control the pressure and the direction of the velocity of gas from the different pipes, as well as the amount of the different gas.
When somebody designs the size and shape of branch pipes and general pipe actually, he should make the gas’s condition spout from branch pipes varies as small as possible, and the gas stables at convergence before the turbine.
qumfI think the biggest difficulties to realize the new type of jet engine are:
1. Some parts bear the unstable forces. I calculate and compare the several solutions to choose the best. I change the force condition from initial pulse force; let the parts bear pressure and pull forces alternately and the maximum magnitude of stress becomes smaller a lot. The trend of deformation became the smallest and the whole weight is the smallest. It also need to add a component, however the whole weight will be the lightest. I am not sure that the solution can be applied in each part has the situation.
2. To regulate the work procedure for high efficiency, safety, and economical is necessary but a little hard, but the jet have to work under many circumstances. The simple countermeasures are: 1. to set the engine rotation speed within a certain range while working. Out off the range the engine will be inefficient, even dangerous. 2. Sometimes we need to change the proportion of fuel to air to get different performance; the jet can work steadily without additional adjustment. Even though the volume of the fresh gas in once input changes, the jet also can work normally. 3. If necessary we can add openings or bypass on the general pipe.
As to the components bearing the heat load in the type of jet, I have some ideas:
1. Sometimes the chambers touch the burning gas in some position, but the rather higher temperature last a very short time. When the fresh gas enters the chambers, the chambers are cooled.
2. At some position in some components, such as inner side of the front door and back door of the chambers, they touch very high temperature gas all the time. I think out a solution: When the doors (round plates) will close, from their inner side, near the edge, discharge some fresh air to separate the burning gas to the inner side of the doors.
3. Some surfaces in some parts always touch very high temperature gas, but the stress isn’t rather bad. I can choose proper structure and material on the surfaces to bear high temperature.
qumfFeasibility and improvement solution:
When I firstly proposed the idea in my patent(That patent has been out of valid time), I didn’t use the blower or compressor in my engine. Now I prefer to adopt the blower/compressor in engine before combustion after I think it over. It really has a lot of advantages.
1. Without the blower/compressor the engine may have difficulty to be started or on work in slow speed because it may not get enough air.
2. Increasing pressure of air before combustion can increase efficiency considerably.
3. Without compression before combustion, the size of chamber will be much bigger; sometimes the mixture isn’t easily to be ignited.
4. Adopt compression before combustion, the engine easily to keep orderly work under a little variable situation.
5. If feasible we can add fuel in into air gradually to form mixture at the position of some portion of blower/compressor, maybe blades, or install additional device.
6. If increasing the pressure extremely high before combustion, the mixture gas might be ignited by itself. It is not safe under some case. So I have to improve the structure.
Later I have an idea. We can set the branch pipes in front of the chambers, there are a pairs or two pairs of the branch pipes(or relative space) that are corresponding to the chambers while the gas enter them. The branch pipes rotate with the front door, it won’t cost much energy. Thus the gas before chambers always flows in high speed flow condition, Thus the gas is hard to burn, even though it will, it has entered the chambers when it burn.
The internal space of the front door becomes much large than the previous. We also can utilize the space install some devices to cool front door, separate the heat from gas by another air, is good for seal and so on.
Temporary I don’t update the structure picture upper.
qumfCalculate the temperature before the turbine:
Pls see below figure 4:
[ATTACH]199400[/ATTACH]
The method also is used to calculate the temperature of each course. Under some condition, when the pressure after compression is pretty high, reducing the pressure by combustion in some extent, the efficiency reduce a little, meanwhile the temperature before turbine reduce much, I state a example:
Set the temperature of outside air: 300K, k=1.4, set the pressure after compression/before compression α=7, the pressure after combustion/before combustion β=7.5, thus the temperature turbine 2206K; theory efficiency: η=60.2%； k=1.4, α=7, β=7, the temperature turbine 2100K, η=59.6%; k=1.4, α=7, β=6.5, the temperature turbine 1992K, η=58.9%; k=1.4, α=7, β=6, the temperature turbine1881K, η=58.2%; I change β by change in the volume proportion of fresh gas in each time or change of the concentration of fuel a little. In this example, η is reduced by 3%, the temperature before turbine decrease 400K.
———————————————
This example just reminds a phenomenon. The data to some parameters may not be precise; actually they are variable normally and very high temperature. Here I assume them unvaried. After all it is a good reference for you.
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