---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Fri 08/25/23: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:10 AM - Re: Re: Cabin fresh air exhaust (Bud Yerly) 2. 08:04 AM - Re: Cabin fresh air exhaust (Area-51) 3. 08:09 AM - Re: Re: Cabin fresh air exhaust (Bud Yerly) 4. 09:19 AM - Re: Re: Cabin fresh air exhaust (Bud Yerly) 5. 09:59 AM - Re: Cabin fresh air exhaust (Erich Trombley) 6. 10:13 AM - Re: Re: Cabin fresh air exhaust (Pete Zut) 7. 10:15 AM - Re: Re: Cabin fresh air exhaust (Pete Zut) 8. 03:31 PM - Re: Cabin fresh air exhaust (Area-51) 9. 03:51 PM - Re: Re: Cabin fresh air exhaust (Pete) 10. 04:28 PM - Re: Cabin fresh air exhaust (Area-51) 11. 05:49 PM - Re: Re: Cabin fresh air exhaust (Mike Christine Duane) ________________________________ Message 1 _____________________________________ Time: 07:10:40 AM PST US From: Bud Yerly Subject: RE: Europa-List: Re: Cabin fresh air exhaust I was staring at work that needs to be done and my N12AY was setting in the corner of the shop and I noticed something I missed on ventilation exhaust. The two curvy slots for the flap exit could easily have a small ramp added to it to draw air out of these slots. I'm wondering if that would be a reasonable experiment to do in the future. The flaps are about 1/8 inch from the upper surface to the fuselage on 12AY but the bottom is slightly wider and of course as the flaps extend the gap between fuselage and flap increases further. Just another tweak in my life. Maybe I'll do that this fall. Best Regards, Bud Yerly -----Original Message----- From: owner-europa-list-server@matronics.com On Behalf Of Area-51 Sent: Thursday, August 24, 2023 9:02 PM Subject: Europa-List: Re: Cabin fresh air exhaust Yes, fancy way of describing noise and padding out the content with exciting and conversational inspiring fodder :) Fully agree with all Bud's points. Somebody at the beginning mentioned a reversed naca vent arrangement so that's what got reviewed but other exhaust arrangements can be played with at some later stage. At this point it has been established that providing a cabin exhaust vent to the outside improves flow through capacity of cabin ventilation. Belly mounted exhaust vents downstream of the rear cabin wall along with a vent at the wall is probably a suitable position as the air flow is already a bit dirty from the cowling shape and mono undercarriage and would assist sucking out any undesirable vapor or smoke should that arise. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=511344#511344 ________________________________ Message 2 _____________________________________ Time: 08:04:03 AM PST US Subject: Europa-List: Re: Cabin fresh air exhaust From: "Area-51" Do a quick explanation sketch Bud. Played with this a bit more today by adding an additional belly vent aft of the curtis valves; then another pair of vents just below the leading edge of the Hstab; then added a passage through the D panel. The top mounted exit vent provides the most volume flow through the entry vents into the cabin. However eliminating both top and belly exit vents and retaining the D panel port and rear exit vents provides a more uniform flow and less disturbance to exterior free stream air upon exit. The model being tested has the flap bar slots blocked off; there would normally be air exiting or entering from this area; which is possibly where CO is getting in from prop swirl turbulence. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=511346#511346 Attachments: http://forums.matronics.com//files/265a1925_eb01_456b_8802_0f8517d5ecf1_104.jpeg http://forums.matronics.com//files/9af75de8_4e70_4efb_9765_43b18375d65e_102.jpeg http://forums.matronics.com//files/b50caad2_2c77_4c00_9c54_53d9b7dc259f_109.jpeg http://forums.matronics.com//files/e4802158_03c5_407b_85b5_e685cf82039d_788.jpeg ________________________________ Message 3 _____________________________________ Time: 08:09:17 AM PST US From: Bud Yerly Subject: RE: Europa-List: Re: Cabin fresh air exhaust I'll take some time tonight. Bud -----Original Message----- From: owner-europa-list-server@matronics.com On Behalf Of Area-51 Sent: Friday, August 25, 2023 11:04 AM Subject: Europa-List: Re: Cabin fresh air exhaust Do a quick explanation sketch Bud. Played with this a bit more today by adding an additional belly vent aft of the curtis valves; then another pair of vents just below the leading edge of the Hstab; then added a passage through the D panel. The top mounted exit vent provides the most volume flow through the entry vents into the cabin. However eliminating both top and belly exit vents and retaining the D panel port and rear exit vents provides a more uniform flow and less disturbance to exterior free stream air upon exit. The model being tested has the flap bar slots blocked off; there would normally be air exiting or entering from this area; which is possibly where CO is getting in from prop swirl turbulence. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=511346#511346 Attachments: http://forums.matronics.com//files/265a1925_eb01_456b_8802_0f8517d5ecf1_104.jpeg http://forums.matronics.com//files/9af75de8_4e70_4efb_9765_43b18375d65e_102.jpeg http://forums.matronics.com//files/b50caad2_2c77_4c00_9c54_53d9b7dc259f_109.jpeg http://forums.matronics.com//files/e4802158_03c5_407b_85b5_e685cf82039d_788.jpeg ________________________________ Message 4 _____________________________________ Time: 09:19:52 AM PST US From: Bud Yerly Subject: RE: Europa-List: Re: Cabin fresh air exhaust A quickie sketch at lunch time. Just a small ramp fabbed and then tapered to clear the flap may draw a bit of air out of these rather ugly gaps in the aircraft side. However ugly th ese slots may appear to be, and we do pretty them up slightly, but it makes for expedient construction and my thought was it may be a useable exit for cockpit air ventilation. The ramp will have to clear the lower edge of the flap as it extends initia lly so on my plane 5mm may be maximum height. I'm thinking I may just do a quick photo, and 3D print a rough ramp so it can be tapped in place (3M st icky two sided tape most likely to preserve my patience.) I would think ju st stick it on and go fly. Put a small pressure sensor / Arduino and check outside pressure vs inside pressure to determine the effectiveness. Personally, my pressure vents are fine except for the pilot side NACA which is too low and allows exhaust fumes to enter when climbing from 75-90 Knot s climb speeds. At cruise my pilot side NACA duct is free of exhaust fumes . I'm thinking longer exhaust pipe. Time and energy permitting of course. That thinkin stuff will get you in trouble. Bud Yerly -----Original Message----- From: owner-europa-list-server@matronics.com On Behalf Of Area-51 Sent: Friday, August 25, 2023 11:04 AM Subject: Europa-List: Re: Cabin fresh air exhaust > Do a quick explanation sketch Bud. Played with this a bit more today by adding an additional belly vent aft of the curtis valves; then another pair of vents just below the leading edge of the Hstab; then added a passage through the D panel. The top mounted exit vent provides the most volume flow through the entry v ents into the cabin. However eliminating both top and belly exit vents and retaining the D panel port and rear exit vents provides a more uniform flow and less disturbance to exterior free stream air upon exit. The model being tested has the flap bar slots blocked off; there would norm ally be air exiting or entering from this area; which is possibly where CO is getting in from prop swirl turbulence. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=511346#511346 Attachments: http://forums.matronics.com//files/265a1925_eb01_456b_8802_0f8517d5ecf1_104 .jpeg http://forums.matronics.com//files/9af75de8_4e70_4efb_9765_43b18375d65e_102 .jpeg http://forums.matronics.com//files/b50caad2_2c77_4c00_9c54_53d9b7dc259f_109 .jpeg http://forums.matronics.com//files/e4802158_03c5_407b_85b5_e685cf82039d_788 .jpeg ________________________________ Message 5 _____________________________________ Time: 09:59:58 AM PST US From: Erich Trombley Subject: Europa-List: Re: Cabin fresh air exhaust Hello all, I appreciate the discussion this thread had yielded. So, in my case I have a ram air NACA duct in the lower cowl which provides more than sufficient airflow to the two eyeball vents located in the lower portion of the center instrument panel. The challenge I have, as previously mentioned, is getting the air to exit the cockpit in order to relieve the pressure which causes excessive bowing of the door frames. Unfortunately, the standoffs on the D panel arent sufficient on their own, and I currently have just the pax door seal on at the moment. If I understand the latest analysis by Area-51 an exit near the horizontal stabilator may do the trick. This may also require longer standoffs on my D panel if that becomes the flow constraint. I am also interested in hearing from Pete who has a reverse NACA installed just aft of the doors on the top of the canopy. Noise and weather concerns notwithstanding, does this solution get the job done? Thanks everyone for providing their time and energy to this question. Erich Trombley N28ET Classic Mono 914 ________________________________ Message 6 _____________________________________ Time: 10:13:48 AM PST US From: Pete Zut Subject: Re: Europa-List: Re: Cabin fresh air exhaust wrt to Troy's reverse Naca behind the doors on top, I am not convinced it makes much of a difference. Hopefully I will get up soon again and check it out at various airspeeds (I've been grounded the last two weeks due to recovery from surgery ....) Cheers, PeteZ On Fri, Aug 25, 2023 at 1:07=AFPM Erich Trombley wrote: m > > > > Hello all, > > I appreciate the discussion this thread had yielded. So, in my case I > have a ram air NACA duct in the lower cowl which provides more than > sufficient airflow to the two eyeball vents located in the lower portion of > the center instrument panel. The challenge I have, as previously > mentioned, is getting the air to exit the cockpit in order to relieve the > pressure which causes excessive bowing of the door frames. Unfortunately , > the standoffs on the D panel aren=99t sufficient on their own, and I > currently have just the pax door seal on at the moment. > > If I understand the latest analysis by Area-51 an exit near the horizonta l > stabilator may do the trick. This may also require longer standoffs on my > D panel if that becomes the flow constraint. > > I am also interested in hearing from Pete who has a reverse NACA installe d > just aft of the doors on the top of the canopy. Noise and weather > concerns notwithstanding, does this solution get the job done? > > Thanks everyone for providing their time and energy to this question. > > Erich Trombley > N28ET > Classic Mono 914 > =========== =========== =========== =========== =========== > > ________________________________ Message 7 _____________________________________ Time: 10:15:08 AM PST US From: Pete Zut Subject: Re: Europa-List: Re: Cabin fresh air exhaust Looks like the trim slots are candidates for exhaust? On Fri, Aug 25, 2023 at 11:11=AFAM Area-51 wrote: > goldsteinindustrial@gmail.com> > > Do a quick explanation sketch Bud. > > Played with this a bit more today by adding an additional belly vent aft > of the curtis valves; then another pair of vents just below the leading > edge of the Hstab; then added a passage through the D panel. > > The top mounted exit vent provides the most volume flow through the entry > vents into the cabin. However eliminating both top and belly exit vents a nd > retaining the D panel port and rear exit vents provides a more uniform fl ow > and less disturbance to exterior free stream air upon exit. > > The model being tested has the flap bar slots blocked off; there would > normally be air exiting or entering from this area; which is possibly whe re > CO is getting in from prop swirl turbulence. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=511346#511346 > > > Attachments: > > > http://forums.matronics.com//files/265a1925_eb01_456b_8802_0f8517d5ecf1_1 04.jpeg > > http://forums.matronics.com//files/9af75de8_4e70_4efb_9765_43b18375d65e_1 02.jpeg > > http://forums.matronics.com//files/b50caad2_2c77_4c00_9c54_53d9b7dc259f_1 09.jpeg > > http://forums.matronics.com//files/e4802158_03c5_407b_85b5_e685cf82039d_7 88.jpeg > > =========== =========== =========== =========== =========== > > ________________________________ Message 8 _____________________________________ Time: 03:31:10 PM PST US Subject: Europa-List: Re: Cabin fresh air exhaust From: "Area-51" Peter the trim slots are shielded by a forward bulkhead feature on 181, so air flow to these slots is very limited. Implementing rear side exhaust ports near the Hstab has its own set of challenges and issues regarding structural integrity and fatigue of the Hstab root area. Some tricky "multi-phase" solutions are required on this subject to factor in prop swirl and exhaust gas paths from the engine's tail pipe; which means a "press Solve button and go to bed" situation. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=511352#511352 ________________________________ Message 9 _____________________________________ Time: 03:51:15 PM PST US From: Pete Subject: Re: Europa-List: Re: Cabin fresh air exhaust Area of the bulkhead slot isnt any smaller than my existing reverse naca behind the doors fwiw. > On Aug 25, 2023, at 6:40 PM, Area-51 wrote: > > > Peter the trim slots are shielded by a forward bulkhead feature on 181, so air flow to these slots is very limited. > > Implementing rear side exhaust ports near the Hstab has its own set of challenges and issues regarding structural integrity and fatigue of the Hstab root area. > > Some tricky "multi-phase" solutions are required on this subject to factor in prop swirl and exhaust gas paths from the engine's tail pipe; which means a "press Solve button and go to bed" situation. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=511352#511352 > > > > > > > > > ________________________________ Message 10 ____________________________________ Time: 04:28:43 PM PST US Subject: Europa-List: Re: Cabin fresh air exhaust From: "Area-51" If you have cutouts in the bulkhead through to the trim slots then air will probably flow out of there, and it could also just as easily get sucked in. Without the D panel port the rear situated exhaust vents showed a tendency to suck air in at 100kt. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=511355#511355 ________________________________ Message 11 ____________________________________ Time: 05:49:48 PM PST US From: Mike Christine Duane Subject: Re: Europa-List: Re: Cabin fresh air exhaust I would imagine that if someone finds a way to remove air from the rear of the fuselage, whether through reverse NACA vents under the stabilators=C2 -or if Bud can figure out a way of removing air through the flap vents, t hen standoffs under the =9CD=9D panel could help draw air out o f the cabin.Now a drawback would be if the pressure drop inside the cabin m ight start bringing in more exhaust fumes on the mono?Does=C2-anybody hav e any concern of=C2-any structural issues with a flap-style vent=C2-on top behind=C2-the doors? Mike DuaneN377EA=C2-Europa XS Conventional GearChandler, AZ Sent from the all new AOL app for iOS On Friday, August 25, 2023, 10:00 AM, Erich Trombley wrote: Hello all, I appreciate the discussion this thread had yielded.=C2- So, in my case I have a ram air NACA duct in the lower cowl which provides more than suffic ient airflow to the two eyeball vents located in the lower portion of the c enter instrument panel.=C2- The challenge I have, as previously mentioned , is getting the air to exit the cockpit in order to relieve the pressure w hich causes excessive bowing of the door frames.=C2- Unfortunately, the s tandoffs on the D panel aren=99t sufficient on their own, and I curre ntly have just the pax door seal on at the moment.=C2- If I understand the latest analysis by Area-51 an exit near the horizontal stabilator may do the trick.=C2- This may also require longer standoffs o n my D panel if that becomes the flow constraint.=C2- I am also interested in hearing from Pete who has a reverse NACA installed just aft of the doors on the top of the canopy.=C2- Noise and weather con cerns notwithstanding, does this solution get the job done? Thanks everyone for providing their time and energy to this question. Erich Trombley N28ET Classic Mono 914 S - WIKI - - =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin. ------------------------------------------------------------------------------------- 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.