Eric wrote:
I think I have the same lamp, its very thin brushed stainless steel. Im not sure if I want to rip it apart or not.... very tempting... must resist.... such inner conflict..... arrrggghhh
Ogge, you are welcome to participate in any thread, provided you follow a general decorum.
Not understanding how pulsejets work is ok, asking questions to experienced people about how these things work is GREAT!
What I dont like is once someone trys to tell you what is going on inside a pulsejet, and trys to help you understand, you all of a sudden:
A) become a pulseating combustion genius and pull BS theories out of your ass and tell the very people who you were asking for help that they are wrong. or
B) Agree with the person in a manner so to make it look like you were misinterpreted even though you went on in lenght and detail about the exact oposite of what you just agreed to.
Eric,
I dont fully understand all pulsejet operation. I am still trying to learn what are the excepted theories and what are unknown as far as you guys are concerned. I never took thermodynamics and I am learning it on my own. Hell I had to go look up nodes and aninode, I didnt know what the hell you guys where talking about. I had forget the term. I am still trying to figure out what design criteria you guys are using. But I do have areas of expertise that others are lacking.
Wave theory I KNOW! I know what im talking about. Im not making it up or pulling it out of my ass. I didnt care about standing wave frequencies at the time, I didnt realize you were talking about standing waves at all.
If you go back through all my posts you will see I have been concentrating on wave propogation since I got here. Check out my proposed CC design thread its full of wave theory. What I mean by wave 'theory' is established theory, not my own!
Waveguilds I know, same goes for pulseshaping and impedance matching in waveguides. Do you realize a pulsejet and a PDE are waveguides?
That is what got me involved in the 1st place. No one is treating them as waveguides. Some of the PDE experiments at Wrigh-Patterson AFB are total ridiculas. It was so obvious no one knew a damn thing about waveguides. Differences of 1/4 lamda (3.75mm in this case) can make a huge difference how waves can propagate thru geometry. They were making blanket statements about what worked and what did not. In their set ups, turning a treaded pipe one or two more turns could have totally changed the recorded results they would have gotten by changing where on the waveform they tried to make a turn or branch or generating a standing wave on a reflective surface.
AC signals and manipulation I know, thats what a EE does. That includes combining all the different waves bouncing arround at different frequencies.
You stated that the signal would be a jumble of frequencies and dismissed it. Yes it would be, but there are ways to get alot of useful information also.
For example, hooking up a spectrum analyzer would give us all the frequencies, how prevelant they are. We could see tempature driffs in primary frequencies, calculate exact tempature variations causing it. Find out the true fundimental of the chemical reaction at the tempatures in a pulsejet. I know the cell size (wavelengths) variations at detonation tempature variations and only the cell size changes but not for deflagration. What does a change in wavelength due to tempature change imply? It implies to me that the chemical frequency is staying constant and the wavelenth is changing. This also holds true for how a waves transports energy. The amplitude, Not the frequency is a measure of the wave energy. As waves travels they get weaker but the tone doesnt change over distance only the volume of sound.
If the frequencies are the same but only wavelenghts different we would have hard proof that only wavelengths change. We know that wavelenght of detonation cell sizes change based on tempature/pressure. Hell evening hooking up an oscilascope and finding the highest frequency sinewave riding the combustion pressure spike would tell us that.
We would know how many harmonics could be generated in standing waves by knowing how high a frequency it is and design for them. Knowing frequencies can allow for changes in design parameter for focusing them. Knowing their reflection, refraction and diffraction properties that can limit design constraints.
I know what Im talking about with chemical properties of fuels during detonation, I have stated that im assuming they are similar during combustion and I still need proof. I had it as a senior level transmition lines (and waveguilds class back in 91) and the prof was a detonation waveguild consultant to NASA. Im NOT making it up. Its not wild speculation, IT FACT as it was taught to me by a recognized expert in the field. But I cant find any documentation on detonation waveguides, it wasnt in our book.
When I am stating a theory or speculation, I tend to say so up front. If its an idea or speculation I put in IMHO! That stands for ("In My Humble Opinion" if you didnt know). If im stating what Im doing or design goals that dont match accepted theory, thats fine too, I will be doing alot of that. I will not always agree even with what you guys hold as sacrid.
An example of this is my ongoing discusson with Bruno. Yes, I know he disagrees with me. I know he thinks im nuts, so be it. I have respect for him. His BCVP gave me a lot of insperation and I told him so privatly. He holds standing waves as sacrid and wont even consider doing things differently. I am going to try. I may fail, but I will learn in the process.
Point out one instance that I was wrong. To my knowledge, the only wrong assumption that I made was pointed out by Larry. I was thinking microwave frequencies on the focusing ability of waves and he pointed out its shortwave (much larger wavelength) and I couldnt focus it as precisely as I wanted and I publicly acknowledged he was correct and I was wrong.
I give references if I have them when possible. I dont know everyone elses educational status. I give them a place to confirm what I am saying if I can find one handy.
Eric wrote:
You see its not that I dont want you participating, and that I dont want you asking questions, or to give opinions, its just when you give your great and all knowing techno bs speaches, and then try to prove that the other people are wrong by citing websites, that you are only contradicting yourself, and otherwise making yourself look like an ass, and wasting everyones time.
I dont give techno bs speeches. I state facts or give my opinion and generally I distiguish between them. I even go back and comfirm most of my facts and correct any errors I find in my posts. I edited the initial post I responded to you, several times. I was angery and had to go back and tone it down. I havent been able to confirm that a statement I made about modulation, that WAS speculation. I took it out of my posts as unconfirmed, I should not have stated it.
As far as my statements about 'Standing waves' I will bet money on it, its FACT. Look it up.
Standing waves are NOT waves. FACT
They do not follow all wave theory or equations. FACT
The equations you stated are wave theory, wave theory doesnt always apply to standing waves. FACT
The correlation is based on wether its property can be derived from the underlying incodent or reflection waves that created it. FACT I think
A wave by DEFINITION travels over time where ALL points of the sinewave pass a given point! FACT
The time frame is the period. A standing wave does not have a period. You cannot use the 1/f formula as period for a standing wave, its invalid. FACT, this is the primary reason its NOT classified a wave.
A node (note its a different term then for a wave for a reason) never moves. FACT
Do you want a link to prove this? I saw it this afternoon.
Movement at an anti-node only oscilates from negative peak to positive peak. FACT you can prove this with a piece of string.
That is the ONLY motion of standing wave, thats even why its called a STANDING wave. FACT
Standing waves are often misunderstood. Well that is an opinion. For example, the drawing you did. You had arrows on the standing wave, were you implying motion of some path that was followed?
Standing waves generate tone, thats easy, blow on a beer bottle. It sets up a standing wave and vibrates the bottle. Also note, that it does not cause major pumping into the bottle, you only need a small air force to set up a large vibration.
Standing waves studies are best found under music and instrument creation information. Standing waves are primarily used for generating sounds. Reducing sound volume is a primary goal in some of the PDE research, thus my desire to try to minimize standing waves resonance. Resonance amplies the sounds. Matter of fact, i think the latin for resonace is 'to sound loudly'.
I have just been refreshing my memory on standing waves for the last few days trying to figure out how you guys were placing intakes and calculating exhaust lenghts. I still havent figured that out.
Matter of fact, had you just stated that you were talking about standing waves after my initial post. I would have appoligized, and stated I was thinking traveling waves. I had just started my standing wave refresher.
Many people can attest that I can be a very laid back and relaxed participant of this forum who has much to offer, but one thing I do not have ANY patience for someone who flip flops around like this. If you do not know how a pulsejet works, ask questions, gain knowledge, learn from the experience, and apply the knowledge.
You need to recognize, you may have been on this board longer. You have some understanding I do not, but I also have a broader range of knowledge and experience as a professional engineer. There are things I will know and understand that you dont, wether you except them or not. I will take any offer of corection but I wont always agree. Wether you agree with me or not but I do enjoy a good debate. If im wrong prove it and I will be glad.
I dont flip flop, if you prove me wrong I will acknowlege it gladly as an clerification. Im here to learn, if I have a wrong assumption I want to know.
My only error with you was jumping to a conclusion about what frequency you were talking about and the tone. I acknoledged that in my next post and even apologized for it. Unfortunitly I think I addressed it to Mike, I got you two confused.
I stated I made a wrong assumption and we were talking about different frequencies.
While my responses to you may be immature, we all have things that cause us to lose our composure (and hey im barely 19), but in general I find the manner that you conduct conversations within a group of people, many of which have built dozens of engines or have been studying pulsejets for close to 40 years or more, to be very disagreable and down right disrespectful to the very reason this forum is here for, especially since you seem to have no pratical knowledge about pulsejets whatsoever.
Eric
Part of that is a character flaw on my part. Im a teacher, when I see something I see as a flaw or where I can impart my knowledge to help I give it. Sometimes where its wanted or not. It can bother some people to have flaws pointed out. Except it or ignore it.
Its never personal, or an attack. Unlike a post about my inteligence and education which has never been remove or appologized for.
As far as disrepectful, I know I jumped on Larry once, then went back and edited my post and apoligized, publicly. You may be misinterpreting my attempt to open a debate to forward theory or try to learn something. But that fact is, pulsejet knowledge has not progressed much in that same 40 years. I want to see it pushed forward. The only way to do that is to question the status quo.
As far as never building a pulsejet, so what. Im not a welder or metal worker but I am a senior engineer. I didnt build the F-22s either but I was an engineer at Lockheed. I did stand next the the F-22 #1 on the flightline. I may never build one myself, but that does not mean I cant design one or debate on theory or just provide a different perspective. Pezman is the only other Electrical Engineer that im aware of on this board. There are huge overlaps between EE and pulsejets even though Bruno is trying to discourage some of it.
Im here to learn, and hopefully make sure everyone is on the same wavelength and to teach. I want to push discussion even if its a controversial topic. Even if it ruffles a few feathers!