HRM Posted March 2, 2019 Report Share Posted March 2, 2019 Just DL'd it--check out the suggested age! My wife would approve as she puts me at the maturity of a 12 YO. Quote Link to comment Share on other sites More sharing options...
0TreeLemur Posted April 28, 2019 Author Report Share Posted April 28, 2019 On 3/1/2019 at 8:29 PM, testwest said: I was not a Mac guy until this program came out. It was so compelling I had to get a Mac to run it. I've got VirtualBox. Any way to get a Mac running in a VM? My day-to-day computer and laptop both run linux. I have a Windoze box to run X-Plane, and to download/install Garmin updates. I really don't want another box laying around for just one app Quote Link to comment Share on other sites More sharing options...
HRM Posted April 30, 2019 Report Share Posted April 30, 2019 On 4/28/2019 at 2:46 AM, Fred₂O said: I've got VirtualBox. Any way to get a Mac running in a VM? My day-to-day computer and laptop both run linux. I have a Windoze box to run X-Plane, and to download/install Garmin updates. I really don't want another box laying around for just one app The Mac runs Berkeley Unix in the background and easily handles Linux in VirtualBox. Ditch the antiquated Windoze and Linux boxes and buy a Mac. Quote Link to comment Share on other sites More sharing options...
0TreeLemur Posted April 30, 2019 Author Report Share Posted April 30, 2019 That is an idea, but my day job involves working in a native linux environment. I've gotten used to being antiquated. That's why I fly a 1967 airplane!!! 1 1 Quote Link to comment Share on other sites More sharing options...
Awful_Charlie Posted May 1, 2019 Report Share Posted May 1, 2019 On 4/28/2019 at 9:46 AM, Fred₂O said: I've got VirtualBox. Any way to get a Mac running in a VM? I got curious and just ran it up Mac OS X in VirtualBox: https://techsviewer.com/install-macos-10-14-mojave-virtualbox-windows/ Downloaded and installed Benchmark - seems to run ok, just need to work out how to open the samples! 1 Quote Link to comment Share on other sites More sharing options...
HRM Posted May 2, 2019 Report Share Posted May 2, 2019 16 hours ago, Awful_Charlie said: ...seems to run ok Looking forward to the follow-up. Quote Link to comment Share on other sites More sharing options...
0TreeLemur Posted May 2, 2019 Author Report Share Posted May 2, 2019 On 5/1/2019 at 4:48 AM, Awful_Charlie said: I got curious and just ran it up Mac OS X in VirtualBox: https://techsviewer.com/install-macos-10-14-mojave-virtualbox-windows/ Downloaded and installed Benchmark - seems to run ok, just need to work out how to open the samples! So- download quota exceeded- Google drive won't let me down load it "at this time". Pretty vague. I was hoping to download it over night to my creaky old Linux box. BTW- @Awful_Charlie your signature block could be read as suggesting that he "eats pizza AND flies". Which brings to mind one of my favorite quotes of all time, by Bill Bryson from the book "English- the Mother Tongue and How it Got That Way": when discussing why English is simultaneously powerful, brief, and notoriously hard for foreigners to learn, Bryson gave as an example of excessive use of homonyms: "Time flies like an arrow, fruit flies like a banana". -UPDATE: I am downloading the other one, the APFS Image. 1 Quote Link to comment Share on other sites More sharing options...
Awful_Charlie Posted May 2, 2019 Report Share Posted May 2, 2019 11 hours ago, Fred₂O said: So- download quota exceeded- Google drive won't let me down load it "at this time". Pretty vague. I was hoping to download it over night to my creaky old Linux box. BTW- @Awful_Charlie your signature block could be read as suggesting that he "eats pizza AND flies". Which brings to mind one of my favorite quotes of all time, by Bill Bryson from the book "English- the Mother Tongue and How it Got That Way": when discussing why English is simultaneously powerful, brief, and notoriously hard for foreigners to learn, Bryson gave as an example of excessive use of homonyms: "Time flies like an arrow, fruit flies like a banana". -UPDATE: I am downloading the other one, the APFS Image. Somewhere on that site there is a link how to get round the download limit (requires you have a google drive account) Well, I did have it working ok! Having downloaded and imported the Mooney files, then set about modifying them to a Bravo, and have succeeded in making the app repeatedly lock up, and can't find the options suggested in the documentation for mount/dismount an engine. Will reset the model and retry, but it's just moved down the list of things to do... I like Bryson too, but cant say if I've read that one 1 Quote Link to comment Share on other sites More sharing options...
0TreeLemur Posted May 10, 2019 Author Report Share Posted May 10, 2019 On 2/27/2019 at 11:53 PM, testwest said: OK! For the OP, Fred2O, here is the drag polar for the M20J, derived from the data in the 1220G POH (which was applicable to our Mooney, a 1977 M20J): Each one of the little "+" symbols is a line in the POH cruise data. For this POH, the best fit to the aggregate data is from the 6000' best power cruise data at 2740 lb GW, and the pink "+"s are from that particular data set. So the zero-lift drag coefficient is .01654, and the best-fit straight line above gives CD = .01654 +.082 CL2 Pretty close to what Skip wrote... that Mooney provided the clean polar as CD = 0.0164 + 0.072CL2 It took a LONG time to enter all that data into Benchmark.....but it could be done for the other models from the POH data. The M20J data are really good though. Curt Lopresti told me during a conversation once about how his dad was so proud of the torque meter they had installed for direct measurement of installed power for the M20J certification, and of course the other two secret weapons were legendary flight test engineers Fen and Dorothy Taylor. So to overcome drag, you need thrust. How much? Using the data set above and about 75% best power cruise, here is what is happening at the prop: Lots of eye candy here. 6000 feet, 75% best power cruise, 150 hp into the prop, 131.2 comes out due to prop efficiency. Even the old McCauley C212 is pretty good at about 87.5% efficiency. To describe this to jet jocks, the M20 goes ~163 knots on ~262 pounds of thrust. This translates to the airplane speed chart for these conditions, here: Cool stuff. Hope you guys like it. Ok, so thanks to @Awful_Charlie I've got Benchmark running in macOSX virtualbox on my Linux machine! Is there a stock set of performance values for the standard Hartzell prop that came on the model C someplace? How about O-360 engine params? It seems that to describe the airframe performance I'll need to collect some data. Guessing I need a bunch of: altitude, OAT, MP, rpm, ff, and Kias in level flight? Can't use the book values because my bird has several speed mods. Jazzed & looking forward to working on this over the weekend! Fred 2 Quote Link to comment Share on other sites More sharing options...
flyer338 Posted January 10, 2021 Report Share Posted January 10, 2021 (edited) I hope it is all right to resurrect this old thread. It is a great thread even for those of us whose calculus ability has evaporated into the mists of time. This thread motivated me to look for a copy of John T. Lowry’s “Performance of Light Aircraft.” It seems to be almost unobtainium. Does anyone have a source for the book? I have checked Amazon and Abe Books, but $80 seems a bit steep; it offends my thrifty nature (some of us are thought to be CB, but I prefer “thrifty”). Edited January 10, 2021 by flyer338 Typos Quote Link to comment Share on other sites More sharing options...
carusoam Posted January 11, 2021 Report Share Posted January 11, 2021 I did a simple search... http://zodiac.myearthjourney.com/files/0 Performance of Light Aircraft.pdf Not sure what to make of it... -a- 2 Quote Link to comment Share on other sites More sharing options...
0TreeLemur Posted January 12, 2021 Author Report Share Posted January 12, 2021 On 1/10/2021 at 9:14 PM, carusoam said: I did a simple search... http://zodiac.myearthjourney.com/files/0 Performance of Light Aircraft.pdf Not sure what to make of it... -a- Awesome. Good find -a- ! 1 Quote Link to comment Share on other sites More sharing options...
0TreeLemur Posted January 4, 2023 Author Report Share Posted January 4, 2023 This is such a great thread for aero-nerds. Bringing it back up for the New Year for the Noo Mooniacs! Quote Link to comment Share on other sites More sharing options...
Pinecone Posted January 4, 2023 Report Share Posted January 4, 2023 Good find for the PDF, as the actual book is about $270 on Amazon. FYI, the major reason you want the wing to stall root first is that if one tip stalls first, the wing drops VIOLENTLY. The original configuration of the Tomahawk was with outboard stall strips only. They wanted the stall to be not so benign for training purposes. These was an SB (maybe an AD) to install inboard stall strips to tame the stall. I did my CFI spin training in a Tomahawk (even though I had done spins in a 7KCAB and 8KACB, Great Lakes, and T-37). The entry was IMPRESSIVE. Basically a half snap roll to inverted, then the nose fell through a become a typical spin. BTW, if you ever spin a Tomahawk, DO NOT LOOK AT THE TAIL. Very scary. It really twists and turns. 1 Quote Link to comment Share on other sites More sharing options...
rbp Posted January 4, 2023 Report Share Posted January 4, 2023 3 hours ago, Pinecone said: FYI, the major reason you want the wing to stall root first is that if one tip stalls first, the wing drops VIOLENTLY. also, if the tip stalls first, you lose aileron effectiveness (not that you're supposed to use it) Quote Link to comment Share on other sites More sharing options...
0TreeLemur Posted January 7, 2023 Author Report Share Posted January 7, 2023 On 1/4/2023 at 1:01 PM, Pinecone said: BTW, if you ever spin a Tomahawk, DO NOT LOOK AT THE TAIL. Very scary. It really twists and turns. I did spin training in a C152. Didn't turn around and look at the tail, but it sounded like five sheets of tin being shaken like dirty rugs. Some serious motion going on there. Quote Link to comment Share on other sites More sharing options...
Raymond J1 Posted January 7, 2023 Report Share Posted January 7, 2023 On 12/12/2018 at 10:56 AM, ArtVandelay said: I understand that. Actually it depends on the wing shape, some go tip to root, some root to tip. It doesn’t happen naturally with Rectangular wings, which is why Mooney has stall strips. I thought that once reaching stall, laminar flow wings lost all lift with greater AOA and that’s why some use vortex generators which effectively turns the wing into a non laminar flow wing. BTW, this is a plot of a jet laminar flow wing, notice the quick reduction in lift, loosing all lift in less than 1° of additional AOA. After research, it depends how laminar flow the wings are and where the separation occurs. Some airfoils are worst then others ( 5-digit NACA series are described as nasty). In this graphic system invented by Mr Gustave Eiffel, who is the creator of coefficients "C" (Cx, Cy, Cz), projections on the triaxis attached to the direction of the speeds. This method was an alternative at the graphic system imagined by Lilienthal (polar representation). For Mr Eiffel, the necessity was to calculate the components of the crosswind and to determine the resistance of the structures to winds with precision. After the creation of the Chalais Meudon aérodynamic wind tunnel, south of Paris, he extended his interpretation to the nascent aeronautics, this is the origin of his work on the Eiffel profiles. The NACA (now NASA) took over this graphic system after WW1. The aerodynamic stall of a profile or a wing has nothing to do with the projection of the resultant "C" on the vertical axis "Z" of the speed trihedron, that is to say "Cz". The curve of "C" is gradued in "incidence" angles. In the "Eiffel" system, the "stall" corresponds to a change in the aerodynamic flow regime, that is to say the moment when the profile leaves the "laminar" flow to undergo the "turbulent" flow. the incidence where this occurs is called "transition incidence". When the NACA in 1934 created its catalog of profiles, after having tested several families of profiles among those of Eiffel, Gottïngen, Staé, RAE, joukowski,..., There was the desire to create profiles where the transition incidence was close to the Cz max or at incidences higher than those of the Cz max. But this does not make it the rule that the "stall" occurs at the incidence of Cz max or after. From 1923 and the invention of the gyroplane, which precisely exploits the property of "stall" (the rotor remains in turbulent regime whatever the incidence), it is demonstrated that a wing knows how to produce a significant lift force, by being constantly "unhooked", with a zero Cz (case of the gyroplane rotor in vertical autorotation where the lift is achieved by the "Cx" component (the rotor drags). Quote Link to comment Share on other sites More sharing options...
1980Mooney Posted January 7, 2023 Report Share Posted January 7, 2023 (edited) On 1/10/2021 at 9:14 PM, carusoam said: I did a simple search... http://zodiac.myearthjourney.com/files/0 Performance of Light Aircraft.pdf Not sure what to make of it... -a- On 1/12/2021 at 10:35 AM, 0TreeLemur said: Awesome. Good find -a- ! On 1/4/2023 at 7:01 AM, Pinecone said: Good find for the PDF, as the actual book is about $270 on Amazon. Wow - all 475 pages (55 MB) in the download - and you don't even need to pay $270 for the book.... I am surprised that someone isn't here already calling us all thieves and accomplices like in the M20L Conversion to Ovation topic last October. https://mooneyspace.com/topic/7846-ovation-1-to-ovation-3-via-the-midwest-stc/?do=findComment&comment=765668 Edited January 7, 2023 by 1980Mooney 1 Quote Link to comment Share on other sites More sharing options...
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