tag:blogger.com,1999:blog-5854741938955568545.post5050008552589897776..comments2019-08-12T01:10:45.285-07:00Comments on ElectricRCAircraftGuy.com--RC, Arduino, Programming, & Electronics: Propeller Static & Dynamic Thrust Calculation - Part 1 of 2Gabriel Stapleshttp://www.blogger.com/profile/10071071884455787806noreply@blogger.comBlogger90125tag:blogger.com,1999:blog-5854741938955568545.post-87347333177865972352019-05-28T13:19:33.470-07:002019-05-28T13:19:33.470-07:00@Unknown, simply search this page's comments f...@Unknown, simply search this page's comments for my previous answer to someone: "From the aircraft's perspective, negative thrust is simply considered to be drag."Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-60006650116767564302019-05-28T11:53:15.221-07:002019-05-28T11:53:15.221-07:00What does that negative dynamic thrust means ??What does that negative dynamic thrust means ??Unknownhttps://www.blogger.com/profile/06977000781998265794noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-43099391621948288132018-08-05T19:08:49.356-07:002018-08-05T19:08:49.356-07:00The links you provide show both are correct.The links you provide show both are correct.Nikhttps://www.blogger.com/profile/07781657524402543545noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-58603322325878198232018-08-05T18:33:35.084-07:002018-08-05T18:33:35.084-07:00Hi, several years late to the party!
Correct me if...Hi, several years late to the party!<br />Correct me if I'm wrong but I'm pretty sure motor torque = current / Kv. So if you're collecting data using a motor with a known Kv, finding torque is as simple as reading current draw, no?Nikhttps://www.blogger.com/profile/07781657524402543545noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-82923372212356976032018-08-01T23:40:32.019-07:002018-08-01T23:40:32.019-07:00I need to know more about the equation. Can i get ...I need to know more about the equation. Can i get your mailid?Unknownhttps://www.blogger.com/profile/03902739710855493652noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-37427346068941945782018-07-27T20:24:47.530-07:002018-07-27T20:24:47.530-07:00*I believe one of your early steps has a flaw*I believe one of your early steps has a flawUnknownhttps://www.blogger.com/profile/16178091206298689906noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-75271449244044700362018-07-27T20:23:56.487-07:002018-07-27T20:23:56.487-07:00One of the early steps of your derivation has a fl...One of the early steps of your derivation has a flaw. Propeller thrust should be derived as <br />F = 0.5 * A * p * (Ve^2 - Vac^2)<br /><br />Sources:<br />https://www.grc.nasa.gov/WWW/k-12/airplane/propanl.html<br />https://www.grc.nasa.gov/WWW/K-12/airplane/propth.htmlUnknownhttps://www.blogger.com/profile/16178091206298689906noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-54661226674424936612018-04-18T08:57:40.416-07:002018-04-18T08:57:40.416-07:00No, sorry, I haven't written any journal paper...No, sorry, I haven't written any journal papers on this. I did it all outside of school and normal work while I was a researcher in an indoor flight lab, but it hasn't been published in any journal. You are welcome to use it obviously but you'll have to just cite my name and website since there's no journal publication to cite for it.Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-11509819541716898542018-04-04T08:15:52.917-07:002018-04-04T08:15:52.917-07:00Have you done any journal paper relating to this. ...Have you done any journal paper relating to this. I would like to cite your work in my senior college design project.Nirmal Shttps://www.blogger.com/profile/02211408032035268136noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-417393323599233182018-03-23T08:59:32.828-07:002018-03-23T08:59:32.828-07:00No, sorry, but if you read my Part 2 article you&#...No, sorry, but if you read my Part 2 article you'll see that the 1.225 in the equation is the density of air in kg/m^3. Maybe you could try replacing that with the density of water, but I haven't done any experiments to see if that gives good results. Remember also, my equation assumes you *know* the RPMs. In other words, I originally planned on using it in-flight where you can measure live RPMs but don't have a thrust stand. Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-66554595541533335212018-03-16T23:23:57.329-07:002018-03-16T23:23:57.329-07:00I need help for underwater propeller calculations....I need help for underwater propeller calculations. Do you have any material regarding it?Unknownhttps://www.blogger.com/profile/11717986800907432899noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-78074440031593985982018-02-24T14:40:13.570-08:002018-02-24T14:40:13.570-08:00Try this calculator: https://rcplanes.online/calc_...Try this calculator: <a href="https://rcplanes.online/calc_motor.htm" rel="nofollow">https://rcplanes.online/calc_motor.htm</a>Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-20464123422240884072017-10-22T22:41:34.388-07:002017-10-22T22:41:34.388-07:00Hi Gabriel! Thanks a lot for this beautiful resear...Hi Gabriel! Thanks a lot for this beautiful research! Its a piece of art! It is guiding me through my college's senior design project. I do have one question however: Could you guide me as to how to calculate the thrust for a 3-blade prop? My project involves a air-water convertible drone. The back prop is a 3 blade rc boat prop with 3"x5.5. Unknownhttps://www.blogger.com/profile/05544872173767256550noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-65454157063771405812017-10-20T14:09:21.178-07:002017-10-20T14:09:21.178-07:00Yes, actually there is! Please provide me links an...Yes, actually there is! Please provide me links and data to your results and papers you write or publish. I'd like to see what you conclude from your work, especially if you do any dynamic thrust work in a wind tunnel or via flight test or something. You can find my email via the "Contact Me" tab at the top of my website.Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-36599976919902727402017-10-19T15:27:53.622-07:002017-10-19T15:27:53.622-07:00By the way, I am doing my graduation project on ca...By the way, I am doing my graduation project on calculating and measuring the thrust force of propellers... If there is something I could do for you, I'd gladly doCan Uluç Birgülerhttps://www.blogger.com/profile/00936632462368219561noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-19567224250243322072017-10-19T15:22:09.713-07:002017-10-19T15:22:09.713-07:00Coooooooool!!! I liked your thinking very much Gab...Coooooooool!!! I liked your thinking very much Gabriel. Also special thanks for replying in just 10 minutes :)Can Uluç Birgülerhttps://www.blogger.com/profile/00936632462368219561noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-31719880297061322022017-10-19T15:20:56.631-07:002017-10-19T15:20:56.631-07:00This comment has been removed by the author.CUBhttps://www.blogger.com/profile/07250216977650649700noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-60646178711343080232017-10-19T09:09:29.750-07:002017-10-19T09:09:29.750-07:00It's my own equation. I didn't extract it ...It's my own equation. I didn't extract it from anywhere/anyone else.Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-73858615115809306512017-10-19T09:08:38.975-07:002017-10-19T09:08:38.975-07:00Yeah, I came up with it. Here's where I descri...Yeah, I came up with it. Here's where I describe my process: <a href="http://www.electricrcaircraftguy.com/2014/04/propeller-static-dynamic-thrust-equation-background.html" rel="nofollow">Propeller Static & Dynamic Thrust Calculation - Part 2 of 2 - How Did I Come Up With This Equation?</a>. I still have some questions about it myself but haven't had time to re-attack the problem for the last several years. Someday I'd like to put some more research and work into it, as I have some more things to learn about propellers and thrust still myself. Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-71665236446907300252017-10-19T08:57:07.289-07:002017-10-19T08:57:07.289-07:00Hi gabriel, do you recall the source you extracted...Hi gabriel, do you recall the source you extracted the dynamic thrust equation?Can Uluç Birgülerhttps://www.blogger.com/profile/00936632462368219561noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-6533486595892890922017-04-25T09:23:36.779-07:002017-04-25T09:23:36.779-07:00My propeller is 10*4.5" (dia 10" pitch 4...My propeller is 10*4.5" (dia 10" pitch 4.5") and if i assume these motors are really moving at 51000 rpm then, according to your calculator. I get a thrust of 33 kg! So is it wrong? I mean the value i got ( thrust of 33 kg) is unreal? Adminhttps://www.blogger.com/profile/13822300689915260990noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-23360275564171244332017-04-25T09:04:00.655-07:002017-04-25T09:04:00.655-07:00I can promise you there is no way in this world on...I can promise you there is no way in this world one of those motors is going to produce 3750g (15kg/4) of thrust. You are off by probably more than a factor of 100. 51000 RPM? I don't know--maybe--when completely <i>unloaded</i>. Claiming that motor can produce 3750g of thrust is probably equivalent to claiming my 4-cylinder car has a 33000 Hp engine. Nope...it doesn't. It doesn't go 2000 mph either. :) Take a look at HobbyKing's brushless motors. Look for ones that have thrust and power specs and recommended props listed, to get a feel for what's required to produce 3750g of thrust, then go from there. Good luck!Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-52091528887417372952017-04-25T08:58:21.562-07:002017-04-25T08:58:21.562-07:00amazon.com/Coreless-51000RPM-Helicopter-Aircraft-m...amazon.com/Coreless-51000RPM-Helicopter-Aircraft-magnetic/dp/B01B1DVWHEAdminhttps://www.blogger.com/profile/13822300689915260990noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-65409013176542575662017-04-25T08:53:16.414-07:002017-04-25T08:53:16.414-07:00https://www.amazon.com/Coreless-51000RPM-Helicopte...https://www.amazon.com/Coreless-51000RPM-Helicopter-Aircraft-magnetic/dp/B01B1DVWHE link is here. I am going to use these motors. This motor is coreless brushless dc motor with 51000 rpm! Adminhttps://www.blogger.com/profile/13822300689915260990noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-55994428733385032432017-04-25T08:15:48.229-07:002017-04-25T08:15:48.229-07:00How are you calculating RPM? I don't even know...How are you calculating RPM? I don't even know how to do that yet. I measure experimentally. Yes, too high RPM will cause propellers to break apart. APC posts RPM limits for their props, for example, <a href="https://www.apcprop.com/Articles.asp?ID=255" rel="nofollow">here</a>. Also, in addition ot my equation, take a look at these calculators here: <a href="http://rcplanes.000webhostapp.com/calc_motor.htm" rel="nofollow">http://rcplanes.000webhostapp.com/calc_motor.htm (motor & prop calc)</a> and <a href="http://rcplanes.000webhostapp.com/calc_thrust.htm" rel="nofollow">http://rcplanes.000webhostapp.com/calc_thrust.htm (static thrust calc)</a>. They may prove useful.Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.com