design engine 2 hours

[PIETRO2002]

I think as soon as you enter the world of work you understand it yourself.. .

Once we were young all, and if we didn't understand it, they made us understand it is the law of life! :

 

[antopippo]

Once we were young all, and if we didn't understand it, they made us understand it is the law of life! :

No, but maybe we didn't understand, I thank you very much, but I would like you to understand what made me mad. I'll tell you tonight

 

[stevie]

I have no, still the drilling equipment. I hoped I wouldn't hear about it anymore.

 

[stevie]

I smell like a carpenter engine, remember?

 

[ramjet]

No, but maybe we didn't understand, I thank you very much, but I would like you to understand what made me mad. I'll tell you tonight

No, tranqui... We're not that curious.

 

[antopippo]

No, tranqui... We're not that curious.

You don't understand anything hahahaha. you have drawn up stories doing all of you. thanks anyway to those who helped me

 

[PIETRO2002]

You don't understand anything hahahaha. you have drawn up stories doing all of you. thanks anyway to those who helped me

I think if you take this discussion properly you'll be very helpful. I think you're a smart person, and you're gonna be a treasurer!

 

[ramjet]

You don't understand anything hahahaha. you have drawn up stories doing all of you. thanks anyway to those who helped me

Maybe I was a little precipitous: I'm sorry, I didn't mean to offend you.
On the contrary: to make you understand my good faith I invite you to study and to do the tesina on an innovative engine and (unfortunately) boycotted by the Masonry and Jewish power.

It is a motor that can produce clean energy and practically inexhaustible: it is the engine that is closed.

find all the details here:

Motore Schietti: la Spiegazione tecnica

domenico-schietti.blogspot.com

 

[Fulvio Romano]

I smell like a carpenter engine, remember?

<https://www.cad3d.it/forum1/threads/aiuto-ingegneria.15216/page-7#post-132518>
not to forget. . .

 

[antopippo]

Maybe I was a little precipitous: I'm sorry, I didn't mean to offend you.
On the contrary: to make you understand my good faith I invite you to study and to do the tesina on an innovative engine and (unfortunately) boycotted by the Masonry and Jewish power.

It is a motor that can produce clean energy and practically inexhaustible: it is the engine that is closed.

find all the details here:

Motore Schietti: la Spiegazione tecnica

domenico-schietti.blogspot.com

I'll take a look at it while I did a first prototype cylinder.

 

[meccanicamg]

I'll take a look at it while I did a first prototype cylinder.

What are you doing with?
Why is it branded racing?
If you want something pushed, you need to change the shape of the fumes from elliptical to rectangular but well-lit. is one of the first things they teach to process old engines for wasp. eliminating the material around the ellipse decreases the incrustations of oil and you have a more immediate discharge of the fumes. Clearly the mantle is thinned.

 

[antopippo]

What are you doing with?
Why is it branded racing?
If you want something pushed, you need to change the shape of the fumes from elliptical to rectangular but well-lit. is one of the first things they teach to process old engines for wasp. eliminating the material around the ellipse decreases the incrustations of oil and you have a more immediate discharge of the fumes. Clearly the mantle is thinned.

is because they are the initials of my name and surname. Thank you very much for the advice. Now I wanted to find a way to calculate the surfaces of the light because doing so I was sure that the surface was lower than the maximum one I can have on this engine.

 

[Vittorio]

is because they are the initials of my name and surname. Thank you very much for the advice. Now I wanted to find a way to calculate the surfaces of the light because doing so I was sure that the surface was lower than the maximum one I can have on this engine.

download merge360 autodesk, it is free for a year.... but then you can always renew it for free and it is better than rhino for the type of your work

 

[wert]

I'll take a look at it while I did a first prototype cylinder.

To be a high school student, I have to say you did a great job, including. I remain perplexed only by the feasibility of the soul, which I think cannot be realized in a piece only but will probably serve more, framed among them, with quite complex courses. the modeler will have to have fun to make those boxes of soul.

 

[antopippo]

download merge360 autodesk, it is free for a year.... but then you can always renew it for free and it is better than rhino for the type of your work

I'll try.

 

[antopippo]

To be a high school student, I have to say you did a great job, including. I remain perplexed only by the feasibility of the soul, which I think cannot be realized in a piece only but will probably serve more, framed among them, with quite complex courses. the modeler will have to have fun to make those boxes of soul.

Thank you very much. I still have to finish the beam and exhaust lights, to make a passage for the water around the drain. I also have to try to see fluid dynamics and once I head with a rdc of 14 I would like to find a way to see the washing. and you must also understand the maximum pressure to check the biella. then I have to make the carter and find a program that once made the carter and the tree helps me find the volume to understand how harmful volume I have.

 

[antopippo]

Here we go. has geometric compression ratio of 14 with hemisphere head calculated recessed and exhaust phase 203 degrees; of travase 140 and suction 215 therefore presents the intersection of phases and in fact it is designed for kart use and therefore of velocity with therefore a compression ratio not too high.

 

[paulpaul]

Why does he leave you puzzled?

because a complete cfd simulation of a motor is not simple, it is matter from specialists, and from how you wrote it seemed I had not well appreciated the difficulty of work (without taking away from your preparation). Anyway I want to try and help you: I am not specifically a designer of two times but I have "touched" the motor industry. take as below as a guideline: it is not necessary to resort to sophisticated simulation software to make a preliminary sizing.

1. the compression ratio of an eight motor hardly exceeds 10-12 for an aspirator, otherwise it is likely to run into detonation. you have taken 14, from what I know we are really borderline with fuel: you need a special gasoline in my opinion, and you will often travel with detonation, especially low regimes and high loads (which in a racing engine should not occur often...but I do not know the rapportation you want to give to change);

2. first I would fix the c/d ratio (race/alesage): within 2t fast is held around 1. your 125 monocylinder will therefore have for example c=d=54 mm (rounded, displacement equal to 124 cm3);

3. placing a compression ratio of 14 therefore, you have a combustion chamber volume of about 9.5 cm3;

4. At this point, you make a nice excel sheet where degree by degree, for an entire rotation of the shaft, instant shift calculations (and volume) of the piston, its speed and its acceleration (will serve you for what comes next). find reports on any applied mechanical text;

5. We start from speed. if we go to see 2t fast, we see that they are placed, like average speed piston u to the max power regime (u = 2cn, with n rpm), around 18-20 m/s, with 25 m/s for motors eight aspired by thrust competition. taking 22 m/s (I realized that you want to pull this engine!), we have n = 12200 rpm (approximately), which is a value however quite in line with this type of 2 note: in a motor, the average piston speed is much more indicative of the speed of rotation, as at the first are proportional the inertial forces, the mechanical losses for friction, the fluid dynamic losses and any sonic times, i.e.

Now, for the calculation of the power, we lack "only" the filling coefficient of the motor and its performance, both of difficult theoretical determination. the first is especially for the two times at cross/reflecting currents such as these, considering the complex fluid dynamics of the washing (a part of the cool short-circuit charge to the unloading, a part remains in the cylinder, and a part of combustion gases remains in the cylinder): it is a difficult to model, but it can be estimated. what you can calculate is the product between performance and filling coefficient, starting from the pme value (effective mean pressure) of similar engines. the pme is the second (after u) of the main parameters of comparison between motors (there are another pair), and it complies in a single parameter the care of fluid dynamics (suction, exhaust), combustion and the lost power for friction. higher, the more the engine "fills well" and "burns well" the mixture. the greater the pme, the greater the its pair, among other things (and also the mechanical loads on the manovellism). for 2t engines of this type, an indicative value of the maximum pme is 15 bar.

6. as mentioned above, the pme is maximum about the maximum torque regime. from the expression of the pme (you find it everywhere) we then calculate the pair considering our displacement: in the example above there is about 30 nm. also this is quite in line with engines of this type;

7. always from the knowledge of the max pme, from the calorific power of the fuel (benzina, 44 mj/kg), from its mix ratio (14, suppose stechiometric operation even if not always will be so) and the suction density (air motor with a little load losses in the ducts, 1.1 kg/m3), we obtain (always from the expression of the pme) the product yield x max filling coefficient to the to couple regime

just return (they are out for work) we can try to hypothesize a typical filling coefficient and check area and beam lights, and then see if it gives us a realistic power.

the objective is to calculate both the performance but above the limit cycle, so to then rise to the gas pressure degree by degree and then to the gas forces (the inertial revenues starting from the masses of the 3d models that you are drawing, but let's say that you can neglect them at this stage) and then make the verification of the tavellism. it could be enough to calculate the maximum combustion end pressure (the one that ends compression you can calculate already).

p.
I recommend, for the basis of the design of the beams and the light areas of a 2t, "internal combustion engines", ferrari: that part is done quite well.

 

[antopippo]

because a complete cfd simulation of a motor is not simple, it is matter from specialists, and from how you wrote it seemed I had not well appreciated the difficulty of work (without taking away from your preparation). Anyway I want to try and help you: I am not specifically a designer of two times but I have "touched" the motor industry. take as below as a guideline: it is not necessary to resort to sophisticated simulation software to make a preliminary sizing.

1. the compression ratio of an eight motor hardly exceeds 10-12 for an aspirator, otherwise it is likely to run into detonation. you have taken 14, from what I know we are really borderline with fuel: you need a special gasoline in my opinion, and you will often travel with detonation, especially low regimes and high loads (which in a racing engine should not occur often...but I do not know the rapportation you want to give to change);

2. first I would fix the c/d ratio (race/alesage): within 2t fast is held around 1. your 125 monocylinder will therefore have for example c=d=54 mm (rounded, displacement equal to 124 cm3);

3. placing a compression ratio of 14 therefore, you have a combustion chamber volume of about 9.5 cm3;

4. At this point, you make a nice excel sheet where degree by degree, for an entire rotation of the shaft, instant shift calculations (and volume) of the piston, its speed and its acceleration (will serve you for what comes next). find reports on any applied mechanical text;

5. We start from speed. if we go to see 2t fast, we see that they are placed, like average speed piston u to the max power regime (u = 2cn, with n rpm), around 18-20 m/s, with 25 m/s for motors eight aspired by thrust competition. taking 22 m/s (I realized that you want to pull this engine!), we have n = 12200 rpm (approximately), which is a value however quite in line with this type of 2 note: in a motor, the average piston speed is much more indicative of the speed of rotation, as at the first are proportional the inertial forces, the mechanical losses for friction, the fluid dynamic losses and any sonic times, i.e.

Now, for the calculation of the power, we lack "only" the filling coefficient of the motor and its performance, both of difficult theoretical determination. the first is especially for the two times at cross/reflecting currents such as these, considering the complex fluid dynamics of the washing (a part of the cool short-circuit charge to the unloading, a part remains in the cylinder, and a part of combustion gases remains in the cylinder): it is a difficult to model, but it can be estimated. what you can calculate is the product between performance and filling coefficient, starting from the pme value (effective mean pressure) of similar engines. the pme is the second (after u) of the main parameters of comparison between motors (there are another pair), and it complies in a single parameter the care of fluid dynamics (suction, exhaust), combustion and the lost power for friction. higher, the more the engine "fills well" and "burns well" the mixture. the greater the pme, the greater the its pair, among other things (and also the mechanical loads on the manovellism). for 2t engines of this type, an indicative value of the maximum pme is 15 bar.

6. as mentioned above, the pme is maximum about the maximum torque regime. from the expression of the pme (you find it everywhere) we then calculate the pair considering our displacement: in the example above there is about 30 nm. also this is quite in line with engines of this type;

7. always from the knowledge of the max pme, from the calorific power of the fuel (benzina, 44 mj/kg), from its mix ratio (14, suppose stechiometric operation even if not always will be so) and the suction density (air motor with a little load losses in the ducts, 1.1 kg/m3), we obtain (always from the expression of the pme) the product yield x max filling coefficient to the to couple regime

just return (they are out for work) we can try to hypothesize a typical filling coefficient and check area and beam lights, and then see if it gives us a realistic power.

the objective is to calculate both the performance but above the limit cycle, so to then rise to the gas pressure degree by degree and then to the gas forces (the inertial revenues starting from the masses of the 3d models that you are drawing, but let's say that you can neglect them at this stage) and then make the verification of the tavellism. it could be enough to calculate the maximum combustion end pressure (the one that ends compression you can calculate already).

p.
I recommend, for the basis of the design of the beams and the light areas of a 2t, "internal combustion engines", ferrari: that part is done quite well.

Thank you very much for the answer tomorrow I read well.

 

[welcome to the machine]

Good job, good job.
a couple of questions: The exhaust duct, if I understand correctly, does it have the axis on the same plane as the engine shaft? so the entry into the pump casing is at 90° compared to the exhaust duct?

the 3rd travase is at 180° from the exhaust light and its fluid vein you lose it immediately from the discharge, even if you can make a well arranged expansion chamber, but you know it well. If I can afford it, you should raise the lower edge of the third travase to improve the flow from the main beams.
I see a very thin traversine and, even if it is exposed to the fresh gases, it is a very "risky" point, so you should definitely work a bit on the fittings of the corners of the beam lights, otherwise....you always hold a couple of fingers on the clutch! ? ah no... you said that the engine goes on a kart. when "sail" the wonderful two times of the bike went on the ground. karting is a little less dangerous. ...
I don't know how you're doing the carter, but when you have something you want to share faces, maybe we can give you a few tips. the volume you call the carter's harmful, obviously depends on how you draw the engine shaft and the carter itself, but assess the volume change for each shaft rotation board is not difficult, you can also do it with an excell sheet. I would design first biella and piston, then the carter (and its volume variations) comes accordingly
a last curiosity: did you put the candle at the center of the burst chamber?