Dear Andrew, it was a plesure to see your demonstration! Much better than mine, also this unit looks pretty cool! I enjoyed your short explanation thanks to share with us! BLADE
Thank you Blade. This two speed FPSE activity came as a surprise me. So I was please to see that you too had recorded it. Do you know of any other video of FPSEs running with high and low speeds? Andrew
@@andrewhall2702 Dear Andrew, I never seen that, but with other type hot air engines I found it. Thermal Lag could work sometimes in oscillating mode with low frequency 2-4Hz and moderated stroke, but with full stroke and rotating flywheel could hit the 1000rpm.
@@AttilaBlade I noticed I could get two modes out of my jumper, perhaps like yours when you pull the rubber band back more or enough for a stronger starting impulse. th-cam.com/video/gyMoPY6KkTs/w-d-xo.html
Very interesting! I'm working on a Stirling engine, meant to measure the behavior when the length inside the engine from one side to the other is the same as (or half of) the wavelength of the soundwave of that frequency. So the pressure wave is made by the piston and bounces back from the other side. Attila Blade ones mentioned that the wavelength inside the regenerator is much shorter than he expected. This makes sense because the actual route of the gas through the regenerator is longer than the length of the regenerator. Also the cooling and heating inside the regenerator will have some effect. Part of the pressure wave will bounce back from the regenerator to the piston on the cool side of the engine. When you have a whole wavelength engine you have three waves, one from the piston bouncing back from the inside of the regenerator, one through the regenerator bouncing back from the end on the hot side, and one from the end of the hot side bouncing back inside the regenerator. When those three pressure waves synchronize I expect a higher efficiency. I came to this when I was optimizing a Stirling engine design program with test data of the GM 4L23, where there was one measurement with a higher than expected efficiency. Somebody sugested that I should not use that measurement because it was obviously an error, but I want to find out whether it is a real higher efficiency caused by oscillation.
Could you share some more information on that design program? I dabbled a little in modelling Stirling engines using more conventional energy equation based models, and I can't help but be interested in other approaches.
@@bartpaaddiator2747 There is a second order version in Java Script. Search on: Stirling engin design program I have the source code version in Quick Basic of that program with a build in optimizer on that site, but I'm not sure it works. That version you can let the program find the optimal parameters for the highest efficiency and/or power. The program expects the pressure to be the same in the whole engine, but that is not the case on a fast running engine like a thermal acoustic one. I did some work to put it in a spreadsheet, but that can still take some months. People did complain that the program is difficult to use, an they are right, despite all the work I did to make it easier. It's not easy to make difficult things easy.
⚠️ God has said in the Quran: 🔵 { O mankind, worship your Lord, who created you and those before you, that you may become righteous - ( 2:21 ) 🔴 [He] who made for you the earth a bed [spread out] and the sky a ceiling and sent down from the sky, rain and brought forth thereby fruits as provision for you. So do not attribute to Allah equals while you know [that there is nothing similar to Him]. ( 2:22 ) 🔵 And if you are in doubt about what We have sent down upon Our Servant [Muhammad], then produce a surah the like thereof and call upon your witnesses other than Allah, if you should be truthful. ( 2:23 ) 🔴 But if you do not - and you will never be able to - then fear the Fire, whose fuel is men and stones, prepared for the disbelievers.( 2:24 ) 🔵 And give good tidings to those who believe and do righteous deeds that they will have gardens [in Paradise] beneath which rivers flow. Whenever they are provided with a provision of fruit therefrom, they will say, "This is what we were provided with before." And it is given to them in likeness. And they will have therein purified spouses, and they will abide therein eternally. ( 2:25 ) ⚠️ Quran
Interestingly, there is a video by @AttilaBlade where he shows a simple free piston engine made out of glass which also has two operating frequencies corresponding to different amplitudes. After a quick look at the Walker and Senft book on free piston Stirling engines, it seems to me that it is reasonable to assume that besides the design stable oscillation, there can be some conditions which will make the engine settle in a different oscillation (meta-stable conditions). But it is frankly difficult to get my head around.
Thanks - I will check out @AttillaBlade. I have also been told that with a coupled twin oscillator system - there are two degrees of freedom and therefore two stable oscillation modes.
@@andrewhall2702 🔴 What Is Islam? 🔴 Islam is not just another religion. 🔵 It is the same message preached by Moses, Jesus and Abraham. 🔴 Islam literally means ‘submission to God’ and it teaches us to have a direct relationship with God. 🔵 It reminds us that since God created us, no one should be worshipped except God alone. 🔴 It also teaches that God is nothing like a human being or like anything that we can imagine. 🌍 The concept of God is summarized in the Quran as: 📖 { “Say, He is God, the One. God, the Absolute. He does not give birth, nor was He born, and there is nothing like Him.”} (Quran 112:1-4) 📚 🔴 Becoming a Muslim is not turning your back to Jesus. 🔵 Rather it’s going back to the original teachings of Jesus and obeying him. More .....👇 🔴 THE RETURN OF JESUS
It seems that they all will go faster if you apply more heat or increase the temperature difference by applying cold to the cold side with a water bath, or ice. Wrap the cooling fins with a wet paper towel and keep it wet and watch it go into a 3 speed or shift to second speed sooner on less heat. Cooling water or ice water on the cooling fins will mean less heat needed to go faster, thereby less chance of seizure of the expanding Piston. Or a high temp ( automotive) plastic/rubber hose, wrapped around the cooling fins in a coil pumping cold water around the cooling fins.
I have not observed this in my stirling engines. Only one operation mode. About 7 Hz and 50 mm amplitude. 2 W output electrical. th-cam.com/video/UQFeBMbmYBY/w-d-xo.html
No - Julian Wood made it 10+? years ago - and then Dennis Cowdery renovated it some 5 years ago. My role has been to study its performance. Thus this question - Do all FPSEs have two stable operational frequencies? Have a look at Dennis' video on the engine th-cam.com/video/oAM6L8kcPL8/w-d-xo.html
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Dear Andrew, it was a plesure to see your demonstration! Much better than mine, also this unit looks pretty cool! I enjoyed your short explanation thanks to share with us! BLADE
Thank you Blade. This two speed FPSE activity came as a surprise me. So I was please to see that you too had recorded it.
Do you know of any other video of FPSEs running with high and low speeds? Andrew
@@andrewhall2702 Dear Andrew, I never seen that, but with other type hot air engines I found it. Thermal Lag could work sometimes in oscillating mode with low frequency 2-4Hz and moderated stroke, but with full stroke and rotating flywheel could hit the 1000rpm.
@@AttilaBlade I noticed I could get two modes out of my jumper, perhaps like yours when you pull the rubber band back more or enough for a stronger starting impulse.
th-cam.com/video/gyMoPY6KkTs/w-d-xo.html
Very nice work
This is a very interesting question, worth working on
Very interesting! I'm working on a Stirling engine, meant to measure the behavior when the length inside the engine from one side to the other is the same as (or half of) the wavelength of the soundwave of that frequency. So the pressure wave is made by the piston and bounces back from the other side.
Attila Blade ones mentioned that the wavelength inside the regenerator is much shorter than he expected. This makes sense because the actual route of the gas through the regenerator is longer than the length of the regenerator. Also the cooling and heating inside the regenerator will have some effect.
Part of the pressure wave will bounce back from the regenerator to the piston on the cool side of the engine.
When you have a whole wavelength engine you have three waves, one from the piston bouncing back from the inside of the regenerator, one through the regenerator bouncing back from the end on the hot side, and one from the end of the hot side bouncing back inside the regenerator. When those three pressure waves synchronize I expect a higher efficiency.
I came to this when I was optimizing a Stirling engine design program with test data of the GM 4L23, where there was one measurement with a higher than expected efficiency. Somebody sugested that I should not use that measurement because it was obviously an error, but I want to find out whether it is a real higher efficiency caused by oscillation.
Could you share some more information on that design program? I dabbled a little in modelling Stirling engines using more conventional energy equation based models, and I can't help but be interested in other approaches.
@@bartpaaddiator2747 There is a second order version in Java Script.
Search on: Stirling engin design program
I have the source code version in Quick Basic of that program with a build in optimizer on that site, but I'm not sure it works. That version you can let the program find the optimal parameters for the highest efficiency and/or power. The program expects the pressure to be the same in the whole engine, but that is not the case on a fast running engine like a thermal acoustic one.
I did some work to put it in a spreadsheet, but that can still take some months. People did complain that the program is difficult to use, an they are right, despite all the work I did to make it easier. It's not easy to make difficult things easy.
⚠️ God has said in the Quran:
🔵 { O mankind, worship your Lord, who created you and those before you, that you may become righteous - ( 2:21 )
🔴 [He] who made for you the earth a bed [spread out] and the sky a ceiling and sent down from the sky, rain and brought forth thereby fruits as provision for you. So do not attribute to Allah equals while you know [that there is nothing similar to Him]. ( 2:22 )
🔵 And if you are in doubt about what We have sent down upon Our Servant [Muhammad], then produce a surah the like thereof and call upon your witnesses other than Allah, if you should be truthful. ( 2:23 )
🔴 But if you do not - and you will never be able to - then fear the Fire, whose fuel is men and stones, prepared for the disbelievers.( 2:24 )
🔵 And give good tidings to those who believe and do righteous deeds that they will have gardens [in Paradise] beneath which rivers flow. Whenever they are provided with a provision of fruit therefrom, they will say, "This is what we were provided with before." And it is given to them in likeness. And they will have therein purified spouses, and they will abide therein eternally. ( 2:25 )
⚠️ Quran
@@user-xy7bt8qg8k Keep your religious views to yourself, we are dealing with physics facts.
Interestingly, there is a video by @AttilaBlade where he shows a simple free piston engine made out of glass which also has two operating frequencies corresponding to different amplitudes. After a quick look at the Walker and Senft book on free piston Stirling engines, it seems to me that it is reasonable to assume that besides the design stable oscillation, there can be some conditions which will make the engine settle in a different oscillation (meta-stable conditions). But it is frankly difficult to get my head around.
Thanks - I will check out @AttillaBlade.
I have also been told that with a coupled twin oscillator system - there are two degrees of freedom and therefore two stable oscillation modes.
This is the link for @Attilablade and another two speed FPSE
th-cam.com/video/s9G2hYBAd64/w-d-xo.html
@@andrewhall2702 🔴 What Is Islam?
🔴 Islam is not just another religion.
🔵 It is the same message preached by Moses, Jesus and Abraham.
🔴 Islam literally means ‘submission to God’ and it teaches us to have a direct relationship with God.
🔵 It reminds us that since God created us, no one should be worshipped except God alone.
🔴 It also teaches that God is nothing like a human being or like anything that we can imagine.
🌍 The concept of God is summarized in the Quran as:
📖 { “Say, He is God, the One. God, the Absolute. He does not give birth, nor was He born, and there is nothing like Him.”} (Quran 112:1-4) 📚
🔴 Becoming a Muslim is not turning your back to Jesus.
🔵 Rather it’s going back to the original teachings of Jesus and obeying him.
More .....👇
🔴 THE RETURN OF JESUS
It seems that they all will go faster if you apply more heat or increase the temperature difference by applying cold to the cold side with a water bath, or ice.
Wrap the cooling fins with a wet paper towel and keep it wet and watch it go into a 3 speed or shift to second speed sooner on less heat.
Cooling water or ice water on the cooling fins will mean less heat needed to go faster, thereby less chance of seizure of the expanding Piston.
Or a high temp ( automotive) plastic/rubber hose, wrapped around the cooling fins in a coil pumping cold water around the cooling fins.
Hi Ray - thanks for your comments vs cooling and using that as a way of getting a bigger delta T
Could you do a video of your engine with two speeds?
I have not observed this in my stirling engines. Only one operation mode. About 7 Hz and 50 mm amplitude. 2 W output electrical. th-cam.com/video/UQFeBMbmYBY/w-d-xo.html
Hey Andrew, did you build it ?
No - Julian Wood made it 10+? years ago - and then Dennis Cowdery renovated it some 5 years ago. My role has been to study its performance.
Thus this question - Do all FPSEs have two stable operational frequencies?
Have a look at Dennis' video on the engine
th-cam.com/video/oAM6L8kcPL8/w-d-xo.html
Thank you so much for this answer.@@andrewhall2702