---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Wed 03/22/23: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:54 AM - Re: the Obsidian Files - So Much Noise!!! (Area-51) 2. 07:00 AM - Re: the Obsidian Files - So Much Noise!!! (n7188u) 3. 07:24 AM - Re: Re: the Obsidian Files - So Much Noise!!! (Pete) 4. 07:35 AM - Re: the Obsidian Files - So Much Noise!!! (n7188u) 5. 07:51 AM - Re: the Obsidian Files - So Much Noise!!! (n7188u) 6. 07:54 AM - Re: Re: the Obsidian Files - So Much Noise!!! (Pete) 7. 08:23 AM - Re: the Obsidian Files - So Much Noise!!! (n7188u) 8. 11:06 AM - What did you do with your Europa this week 19/03/23 (Erich Trombley) 9. 01:39 PM - Re: What did you do with your Europa this week 19/03/23 (n7188u) 10. 03:59 PM - Re: the Obsidian Files - So Much Noise!!! (Area-51) 11. 04:02 PM - Re: What did you do with your Europa this week 19/03/23 (Area-51) 12. 04:31 PM - Re: Re: What did you do with your Europa this week 19/03/23 (Pete Zut) 13. 04:53 PM - Re: What did you do with your Europa this week 19/03/23 (Area-51) 14. 05:42 PM - Re: Re: What did you do with your Europa this week 19/03/23 (Pete) ________________________________ Message 1 _____________________________________ Time: 04:54:52 AM PST US Subject: Europa-List: Re: the Obsidian Files - So Much Noise!!! From: "Area-51" Experiments and discoveries are moving forward over the past few days with some entertaining results. A rudimentary study of some baffle concepts were drafted and run through the simulator; the variations happened by accident due to forgetting to half the density consumption to rpm speed; so the elongated porting was developed and employed on these over calculated equations of x2 actual rpm; once recalibrated the results were pleasing on all the variations. Flow analysis through the air box was applied at 6000, 5500, 5000, 4000 rpm at 1013.25 atmosphere at 20.05C. Filtering for Static Pressure primarily, and Acoustic Energy and Flow Path as added features. Red represents Ambient Atmospheric Pressure which indicates zero restriction to air flow within the airbox at engine rpm. Testing revealed the carburettor porting tubes are slightly undersized causing a pressure drop in these regions at engine speeds above 4000rpm on normally aspirated setups. At 6000rpm the pressure drop equates to approx 600' altitude increase, and at 5500 rpm approx 300' altitude increase, and at 5000rpm around 80' altitude increase. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510475#510475 Attachments: http://forums.matronics.com//files/b4b6c3a5_1516_4c61_9caa_a16ea86d12b7_114.jpeg http://forums.matronics.com//files/5e3d3071_f86a_4ce3_96bf_dbf994ee29de_972.jpeg http://forums.matronics.com//files/79860508_7c0c_4c0d_8f2a_201fdb9d1d25_380.jpeg http://forums.matronics.com//files/dabb99f2_8fec_485f_a172_8d33b4064569_164.jpeg http://forums.matronics.com//files/3c98c93a_9816_4f2f_a91c_abfd458f6483_210.jpeg http://forums.matronics.com//files/532f6ff2_632a_4281_a486_0815710d93d5_189.jpeg ________________________________ Message 2 _____________________________________ Time: 07:00:51 AM PST US Subject: Europa-List: Re: the Obsidian Files - So Much Noise!!! From: "n7188u" Very interesting conversation guys. Part of what makes owning an Europa fun is this type of interaction. I have not been able to fly the airplane enough to reach a conclusion on this most recent mod to my plane. I only flew around 20 minutes last Friday, was windy and bumpy so had other worries in my mind. Tomorrow AM looks nice so will do a short local before work but really want to do a longer x-country to be able to provide an objective conclusion (on the subject of fatigue). But I hate to report that based on that short flight last Friday I did not find that the mod made as large a difference as I was hoping for based on A51's encouraging results. But again, the jury is still out. I think I do detect a slight difference. Maybe a little softer on the high frequency. And I think it is worth keeping the change. But I was hoping for more. Will report again after I get a few longer flights in. Please do keep in mind that I have a paint only interior and, as Bud indicated, I too agree this is a good reason why my Europa is loud. Clive, I still need to go through all the tech discussion in detail (I am at work dealing with other tech discussions) but I did buy a new Bose A 20 when I started flying my Europa. It is incredibly effective at cutting all low frequency noise (prop) but all the high frequency ones seem to go right through making it VERY annoying. In fact, I sometimes switch to my non-ANR headsets and find the low frequency drone much more pleasant (but yes, it is louder). So I will continue evaluating and will provide some final thoughts later on. And all feedback on this subject is greatly appreciated. I think that if I try something in the near future it will be lighter noise insulation on the metal firewall, some quick prototype level interior paneling to see if I can see a change before commuting to that route, and I really wanted to try a wheel pant I have for the mono, maybe in hopes of deflecting air away from the wheel well and reducing turbulence in that area. Chris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510476#510476 ________________________________ Message 3 _____________________________________ Time: 07:24:06 AM PST US From: Pete Subject: Re: Europa-List: Re: the Obsidian Files - So Much Noise!!! Fwiw, Classic, mono, no fairings, panted interior, 912s, stock exhaust, factory cold air intake plenum. My biggliest bang was the softer lords swapout. Before with the stock rubbers the gear whine and harsh compression pulses excited the cabin surfaces and the engine was the most overbearing noise. Post rubbers, the gear whine is below the engine, and the engine is below the 130mph cruise air noise. e-props unique sound signature is more noticable than the WDs when pulling throttle back. I doubt i would have heard that with the stock mounts. High freq engine noise is far below the wind noise. Bose do a fantastic job now. E-props reduced the large start stop excursions (and obvious gearbox dogging) experienced with the WD, nullifying my previously required exhaust and oil reservoir clearancing efforts with the softer lords. Unhappy with bose high freq atten? Try the lightspeeds for comparison lol. I also get a noticeable buffet from my unfared mono wheel, but havent got around to fairing it..watching with interest if you do. Cheers, PeteZ > On Mar 22, 2023, at 10:09 AM, n7188u wrote: > > > Very interesting conversation guys. Part of what makes owning an Europa fun is this type of interaction. > > I have not been able to fly the airplane enough to reach a conclusion on this most recent mod to my plane. I only flew around 20 minutes last Friday, was windy and bumpy so had other worries in my mind. Tomorrow AM looks nice so will do a short local before work but really want to do a longer x-country to be able to provide an objective conclusion (on the subject of fatigue). > > But I hate to report that based on that short flight last Friday I did not find that the mod made as large a difference as I was hoping for based on A51's encouraging results. But again, the jury is still out. > > I think I do detect a slight difference. Maybe a little softer on the high frequency. And I think it is worth keeping the change. But I was hoping for more. Will report again after I get a few longer flights in. > > Please do keep in mind that I have a paint only interior and, as Bud indicated, I too agree this is a good reason why my Europa is loud. > > Clive, I still need to go through all the tech discussion in detail (I am at work dealing with other tech discussions) but I did buy a new Bose A 20 when I started flying my Europa. It is incredibly effective at cutting all low frequency noise (prop) but all the high frequency ones seem to go right through making it VERY annoying. In fact, I sometimes switch to my non-ANR headsets and find the low frequency drone much more pleasant (but yes, it is louder). > > So I will continue evaluating and will provide some final thoughts later on. And all feedback on this subject is greatly appreciated. > > I think that if I try something in the near future it will be lighter noise insulation on the metal firewall, some quick prototype level interior paneling to see if I can see a change before commuting to that route, and I really wanted to try a wheel pant I have for the mono, maybe in hopes of deflecting air away from the wheel well and reducing turbulence in that area. > > Chris > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=510476#510476 > > > > > > > > > ________________________________ Message 4 _____________________________________ Time: 07:35:14 AM PST US Subject: Europa-List: Re: the Obsidian Files - So Much Noise!!! From: "n7188u" Interesting Pete, Since I will probably be removing the engine for painting in the next couple of weeks, does anyone have any dimensions for the new spacers needed to retrofit the Lord mounts? I remember Erich telling me a while back that getting the engine to rest in the correct position took a bit of effort. I could give this a try. Chris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510478#510478 ________________________________ Message 5 _____________________________________ Time: 07:51:32 AM PST US Subject: Europa-List: Re: the Obsidian Files - So Much Noise!!! From: "n7188u" to add one interesting anecdote regarding the noise in my Europa, people tell be that when I fly overhead to enter the pattern (midfield downwind entry is common at my airport due to a Class C at one end of the field) my airplane makes no sound. They can only hear what they think is just wind noise and makes them think it is an electric airplane :) Good job CKT. But inside .... another story. Although I once took a friend up for a ride and he thought I was crazy and that the airplane was not that noisy inside. But he has an F1 Rocket so he may not be a good judge of what a small Rotax powered composite airplane should sound like :) Chris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510479#510479 ________________________________ Message 6 _____________________________________ Time: 07:54:19 AM PST US From: Pete Subject: Re: Europa-List: Re: the Obsidian Files - So Much Noise!!! --- MIME Errors - No Plain-Text Section Found --- A message with no text/plain MIME section was received. The entire body of the message was removed. Please resend the email using Plain Text formatting. HOTMAIL is notorious for only including an HTML section in their client's default configuration. If you're using HOTMAIL, please see your email application's settings and switch to a default mail option that uses "Plain Text". --- MIME Errors No Plain-Text Section Found --- ________________________________ Message 7 _____________________________________ Time: 08:23:59 AM PST US Subject: Europa-List: Re: the Obsidian Files - So Much Noise!!! From: "n7188u" Thanks Pete. Good info. Chris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510481#510481 ________________________________ Message 8 _____________________________________ Time: 11:06:05 AM PST US From: Erich Trombley Subject: Europa-List: What did you do with your Europa this week 19/03/23 The wife and I flew in our Europa to Lake Havasu, AZ (KHII) for lunch with a couple of friends. The weather was just spectacular which was a welcome ch ange. This spring as been cold, wet and windy. Certainly, not your typical Las Ve gas weather. The wife snapped this photo as we starting our decent into our home field. Erich Trombley N28ET Classic Mono 914 ________________________________ Message 9 _____________________________________ Time: 01:39:10 PM PST US Subject: Europa-List: Re: What did you do with your Europa this week 19/03/23 From: "n7188u" Weather here in FL has been a bit wonky. Nice during the week and then not so good on the weekends when I can fly. I did Area-51 mod of insulating the intake air box with sound deadening material (enjoyed being in project mode) and waiting for weather to improve a little to fly more. I am getting ready to paint the airplane. I have bought a good spray gun, a forced air respirator system, got the paint and I am rebuilding my wood frame spray booth. I am going to wait until after Sun'n Fun next week, in case the weather is awesome and decide to fly the airplane there, to start disassembly and painting. I plan to take my time to paint and implement a few changes on the airplane. Chris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510483#510483 ________________________________ Message 10 ____________________________________ Time: 03:59:17 PM PST US Subject: Europa-List: Re: the Obsidian Files - So Much Noise!!! From: "Area-51" Choosing not to fly today; instead thought toward identifying drumming areas of the fuselage; details attached along with required acoustic patch sizes. Some areas of hatches and footwell floor are only accessible for treating during building; footwell floor void could probably be filled with expander foam though. Total added mass can be estimated from sizings. Sizings can be reduced 20% and still remain affective. Mid to forward L/R of centre upper cowl - 4"x10" Mid to forward L/R of centre lower cowl - 3"x12" Naca vent slider door rattle Behind naca vent area to L/E of wing - 6"x10" Fuselage, forward foot well floor step area - 4"x4" Forward hatch fuselage area - 2"x8" Mid centre line to rear hatch hinge - 2"x14" Vert stab rib to fuselage fillet - 4"x30" Vert stab trim bar port area - 4"x8" upper 2"x8" lower Fuselage upper lower seam, fuel filler to L/E of h'stab - 3"x50" Fuselage upper 1/8 quadrant, fuel filler to L/E of h'stab - 4"x45" Fuselage belly, flap hinge covers to static port - 6"x40" Hatches, lower frame 1"x 12" and rear corner sections 6"x8"x8" triangle Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510484#510484 ________________________________ Message 11 ____________________________________ Time: 04:02:07 PM PST US Subject: Europa-List: Re: What did you do with your Europa this week 19/03/23 From: "Area-51" We have been lucky here with conditions past couple of weeks; waiting for winter and cold thick air to arrive... Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510485#510485 ________________________________ Message 12 ____________________________________ Time: 04:31:04 PM PST US From: Pete Zut Subject: Re: Europa-List: Re: What did you do with your Europa this week 19/03/23 It=99s been a fantastic winter season up here in Canuckstan! Lots of snow, but every week has essentially been flyable. I=99ve been getting in an average of about 15hrs/mnth of local zenning-out. Love winter, gooey smooth air, and lotsa white pillow emerge landing spots. Spring has sprung tho, so expecting lotsa rainy weather soon. PeteZ On Mar 22, 2023, at 7:14 PM, Area-51 wrote: gmail.com > We have been lucky here with conditions past couple of weeks; waiting for winter and cold thick air to arrive... Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510485#510485 ________________________________ Message 13 ____________________________________ Time: 04:53:03 PM PST US Subject: Europa-List: Re: What did you do with your Europa this week 19/03/23 From: "Area-51" Magic... what temp is it inside the cockpit during a flight like that? I had 33C on my return leg the other day.. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510487#510487 ________________________________ Message 14 ____________________________________ Time: 05:42:05 PM PST US From: Pete Subject: Re: Europa-List: Re: What did you do with your Europa this week 19/03/23 Always toasty.especially when sunny. I normally have to mix in cold air when its over -10c. PeteZ > On Mar 22, 2023, at 7:58 PM, Area-51 wrote: > > > Magic... what temp is it inside the cockpit during a flight like that? I had 33C on my return leg the other day.. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=510487#510487 > > > > > > > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message europa-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Europa-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/europa-list Browse Digests http://www.matronics.com/digest/europa-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.