Jump to content
Science Forums

The jet propulsion with closed combustion type


Recommended Posts

I have analyzed the efficiency of two kinds of jet engines in theory. What is the actual efficiency of the new jet? While analyzing the efficiency in theory, the efficiency of the compressor and blower is 100%. Actual efficiency of compressor is lower much, about 70%. The blower’s efficiency is higher than the compressor’s. As to the current jet, after combustion a lot of gas energy that can be utilized is absorbed by the turbine for compressor. In the new type jet, the blower also need energy, but proportion is smaller much.

I calculated, with some other conditions, the energy for compressing the gas from 1 bar to 10 bar compare to 1 bar to 1.5 bar, the former is 7 times of the hinder.

From an actual example’s data, as to a current jet engine, 55% of the gas’ energy after combustion that can be utilized is used up by the turbine. That is for the compressor ahead.

Set 70% as the compressor efficiency in the current jet engine, after combustion 55% of energy that can be utilized is absorbed by turbine for compressor. We can get the rate of the actual efficiency to efficiency in theory is 72%

Set 75% as the blower efficiency in the new type jet, after combustion 55%/7=8% of energy that can be utilized is absorbed by turbine for the blower. We can get the rate of the actual efficiency to efficiency in theory is 97.8%

(List the formula per the definition of the heat efficiency: the work done by the gas to outside are same between the actual and theory, but the work from the others to gas is different. They absorbed same quantity of heat. I analyze the two jet engines’ the rate from the actual efficiency to efficiency in theory individually. I get the result upper)

Input the efficiency in theory of two types of jets I said before, the current jet 48%, the new type 42% (These data may not match the example upper, but have the value of reference)

The actual efficiency of the new jet is higher the current jet by 18.6%. So it is completely possible that the actual efficiency of the new jet is higher the current jet by 15- 20%.

The upper analyze is based with the efficiency data upper and ignore some secondary factors. I don’t list the calculation formulas but list the main data in the course. Anybody has interest, I’ll write out.

Link to post
Share on other sites
  • Replies 251
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

looks like the inside of a pulsating shower head. alot like a rodial engine.   purty neat engines here http://www.keveney.com

Dear DFINITLYDISTRUBD:   I suggest firstly you fixed the engine with a shelf. after adjust it ,it can work normally, You let it drive your cart.

dear all:   I always think whether the new jet can work under various conditions. to adopt some cases if it must be adjusted.   In some cases we hope the jet provides less push force than common. I a

Posted Images

first off I'm sorry about the long delay in my responce. I've been quite busy lately with other responcibilities.

 

An automotive A/C system is the Air Conditioning (the system responcible for making cold air out of hot air for comforts sake)

 

[Maybe you machine can work normally but it can’t fly, it is possible that the machine didn’t burning out enough fuel per second to provide enough force/QUOTE]

Considering that the turbo is only a 9" I'd say that it moves quite well!

I look at it this way: total engine weight-20lbs total weight moved 380 lbs+/- a few [email protected] in my experience there aren't many engines that light that can move that much weight that fast, and lastly I get to have fun on the cheap!

Link to post
Share on other sites
Input the efficiency in theory of two types of jets I said before, the current jet 48%, the new type 42% (These data may not match the example upper, but have the value of reference)

The actual efficiency of the new jet is higher the current jet by 18.6%. So it is completely possible that the actual efficiency of the new jet is higher the current jet by 15- 20%.

The upper analyze is based with the efficiency data upper and ignore some secondary factors. I don’t list the calculation formulas but list the main data in the course. Anybody has interest, I’ll write out.

 

In last demonstration, I didn’t input high efficiency value for the new jet, If I input efficiency=44% (U=9.5, W=1.8 pls see the previous explanation about calculation of heat efficiency). Then refer to the previous demonstration about the rate of the actual efficiency to efficiency in theory of two jet engine individually. I conclude the actual efficiency of the new jet is higher than the current jet by 25.6%. It is very good.

Link to post
Share on other sites

9" referes to the outside diameter of the outer turbine on the turbo-charger (the portion of the turbo that is driven by the exhaust from the car or trucks engine). The inner "fan" which moves air perpendicular to the rotation of the turbine is the compressor which in this case is 3" in diameter.

 

Converting it to a jet engine is as simple as fabricating a combustion chamber,

ducting the output of the compressor to the aforementioned chamber with a reed valve between to prevent back-flash, ducting the combustion chamber to the turbine with a reed valve between , fabricating a nozzle to increase exit velocity of exhaust, and last but not least "fabbing up" a throttle body and injector assy. at the intake as well as adding a means of combustion in the combution chamber (glow or spark plug depending on fuel. the best for this aplication comes from the "Eberspacher" auxilery heaters found in older VW Vanagons it is both a glow plug and a spark plug in one when possible it is best to get the fuel and spark management guts with them as it simplifies powering the plugs and regulating fuel flow.)

 

Note: an oil tank, lines and circulator pump are necesary to prevent damage to the bearings of the turbine. (failure to provide adequate lubrication will cause mass destruction of said engine !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!)

 

2. Note: engine weight includes all componants necessary to allow the engine to function properly including fuel pump, battery, fuel management system, combustion management, oil tank and lines, turbine, combustion chamber and ducts, etc .

Link to post
Share on other sites

Hi:DFINITLYDISTRUBD

 

I study what you wrote THOUGH I still have sth not clear.

 

I need remind you sth according to my understand about your explanation:

1. you need modify the turbo-charger, basically make place for other components, such as combustion chambers; pipes and so on.

2. do you think the reed in reed valve has enough strength to bear the high pressure? Pls check and calculate. It would bear 10 bar gas pressure as well as high temperature.

3. do you think the reed can work at the high frequency, at least over 150HZ

4. the reed’s work should avoid energy lost much as possible as it can.

5. What is “a glow plug”?

6. Can you ignite the gas rapidly by electric method at very high frequency?

7. These accessories you noted are necessary to support the jet. For now they are not specialized designed for the new type. Later they will be lighter after improvement.

Link to post
Share on other sites

Hi, DFINITLYDISTRUBD:

 

I forgot to remind you sth:

In my momery, the current in common turbo-charger isn't axial flow.If you need it change the flow's direction to axial get the push force, that would influence the efficiency of engine because it will lost some energy while changing direction.

 

The common turbine is designed for get more energy as much as possible.But it isn't I only desire. I hope the gas still have much energy after turbine to produce push force.

Link to post
Share on other sites

First off thanx GAHD for saving me an explanation!:shrug:

 

Secondly the second reed aparently is not capable of surviving the violent environment of the exhaust stream (post combustion chamber) as upon inspection of my working prototype it is strangly missing (he he!) though the intake reed is fine.

As far as how much pressure it can withstand please note that reed valves have been withstanding the high compression of piston engine use for many years now in everything from gas trimmers to large comercial diesels in tractor-trailors. Also in 2-cycle engines (dirt bike, 4-wheeler, etc.) they are fully capable of opperating at up to 416Hz+ @25,000 rpm.

 

Thirdly as far as ignition rate I'm pretty sure it's nearly constant. Playing around with various goodies I have around the ol shop I've built "sparkies"

that spark at 35Khz. (currently I'm trying for 999Mhz).:eek2:

 

Lastly what the heck is "sth"

Link to post
Share on other sites
Secondly the second reed aparently is not capable of surviving the violent environment of the exhaust stream (post combustion chamber) as upon inspection of my working prototype it is strangly missing (he he!) though the intake reed is fine.

As far as how much pressure it can withstand please note that reed valves have been withstanding the high compression of piston engine use for many years now in everything from gas trimmers to large comercial diesels in tractor-trailors. Also in 2-cycle engines (dirt bike, 4-wheeler, etc.) they are fully capable of opperating at up to 416Hz+ @25,000 rpm.

 

Not only the pressure of the gas the reed bears we should consider, but also we should consider the the size of reed. because they are all related to the force that the reed bears. the force and the strength are different if they have different size even though the reed bear the same pressure of gas. the size is bigger, the strength required is higher.

 

You also should consider the temperature of the gas that the reed bear. that is also important.

 

In my momery, the piston engine's the intake valve and exhaust valve aren't the reed valve type.Why do you the one has the valve?

 

Your 2-cycle engines can work @25000rpm. It is too high. it is out of my image.

Link to post
Share on other sites

In this new type jet engine.

Some parts bear very high temperature, they touch high temperature gas at short time. They also touch cool temperature gas at other time.

2. Some parts touch high temperature gas always, but the temperature is not very high.The density of the gas is small and the "c" of the gas is small also.These parts can be cooled from another side also.

3. Few parts always touch very high temperature gas, such as some place in the front door. If we haven't other method really, we can input cool clean gas through small holes from other place in the front door. (at a certain moment or always). The method can cool the place or isolate the place from the very high temperature gas. We also can input cool air to cool the front door inside or another side.

Link to post
Share on other sites

"Glow plugs are used to heat the combustion chambers of diesel engines in cold conditions to help ignition at coldstart. In the tip of the glow plug is a coil of a resistive wire or a filament which heats up when electricity is connected.

 

Glow plugs are required because diesel engines produce the heat needed to ignite their fuel by the compression of air in the cylinder and combustion chamber." -quote & image coutosy of wikipedia.com

Link to post
Share on other sites
First off thanx GAHD for saving me an explanation!:steering:

As far as how much pressure it can withstand please note that reed valves have been withstanding the high compression of piston engine use for many years now in everything from gas trimmers to large comercial diesels in tractor-trailors. Also in 2-cycle engines (dirt bike, 4-wheeler, etc.) they are fully capable of opperating at up to 416Hz+ @25,000 rpm.

"

 

What is the movement formation of reed in reed valves? Can it allow a lot of gas pass the hole?

Link to post
Share on other sites

In my momery, the piston engine's the intake valve and exhaust valve aren't the reed valve type.Why do you the one has the valve?

 

Your 2-cycle engines can work @25000rpm. It is too high. it is out of my image........................................................................................................................................................................................................

 

technically Yamaha probably never intended for their motorbike motors to be run so hard (20,000 rpm plus) the tachometer on my bike "redlines" (the numbers are red and the motor should not be reved beyond this point) at 16,000 but the numbers go to 25,000 and I as my own personal bike mechanic

have no qualms about "pegging" the needle (reving so high as to push the needle all the way around the guage to the pin the needle rests on when the engine is off). I've personally pushed my 1971 Yamaha 100cc LS2 to speeds in excess of 110+mph (granted it takes a lot of road but it can be done I've heard of speeds exceding 170mph with 100cc bikes)

 

As to reed valves in piston engines most small two strokes some small 4-strokes (Subaru 3-valve 3-cylinder motors come to mind) and all big diesel two strokes have them at least as an intake valve.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...