Saw that kit at Hank Nixon's shop and it's going in my 27 next week. From what I've seen of Dick Butler's creations, doubt I'll be let down too badly. For overnight tiedowns, It might be best to use a Jaxida (or similar) forward fuselage cover. One covered the canopy and engine bay of my 26E, and rolled up into itself for storage. A clear panel was added to allow solar charging for those few daylight hours with the cover on. With this vent and the existing Bumper Morgan "Quiet Vent Kit" the hope is to stay comfortably cool. By the way, you can follow the Concordia project at Soaring Cafe: http://soaringcafe.com/ Jim
________________________________ From: Mike Borgelt <[email protected]> To: Discussion of issues relating to Soaring in Australia. <[email protected]> Sent: Wed, February 23, 2011 8:41:19 PM Subject: Re: [Aus-soaring] Air vent Hi Gary, I don't think that in flight it will be a problem. Hopefully air is coming out at good speed. No worse than dive brake boxes on the ground. Tape it up. The air is going to come out somewhere if you let it in to the cockpit. It may as well come out in one place rather than where it can trip boundary layers, cause noise etc. You must ventilate the cockpit for pilot comfort and safety especially in warm climates. I can only ever remember being cold in a glider once and that includes a ride to 24,700 feet in wave at Minden. I could have gone higher but the non backed up constant flow oxygen system and a decision before made long takeoff that 25,000 was about the reasonable safe limit caused me to break off the climb there. The cold incident was at Gawler one Easter. Jeans and T shirt was quite comfortable on the ground but fairly extensive strato cu cover and climbs to 6500 feet meant that it was near zero up near cloudbase with little solar heating into the cockpit. I tried closing the vent but the canopy instantly started to fog up so I ended up trying to stay warm under a WAC chart. I had an exit vent on my Mini Nimbus, a shallow blister with the back end cut off and a couple of small guides for the flow. Located to one side under the fuselage about in line with the TE of the wing. If the glider is unsealed using an exit vent to reduce the internal pressure can probably make a difference. At the very least it will improve the cockpit ventilation. Take a look at what John Murray of Eastern Sailplane is doing with an exit vent kit for Schleicher gliders. Seems the right idea to collect the low velocity air in the cockpit behind the pilot's head and accelerate it to exit on top of the fuselage over the wing. Don't forget the pressure difference on average between the top of the glider and the bottom is equal to the wing loading. The vent on the JS1 seems to be an attempt to cause the exit air to flow parallel to the skin. I was not impressed by the internal part. No attempt to gather and accelrate the flow inside the fuselage. When doing this we must consider both external and internal flow. Ever looked down the intake of an F86 Sabre? At least ther eis some recognition of the need for exit vents now instead of the actually wrong placements or accidental leaks of the past. I'll have a bit more of a think about this. and try to model the flows and pressures at least qualitatively. Mike At 08:48 PM 23/02/2011, you wrote: >Mike, >I am deleting old emails. >I came across this one of yours. >Re rain ingress - you are an inventive sort of person -do you have >any suggestions? >I note you did not suggest anything at the time. >Is it a problem, other than if the glider is tied down outside? >Have you further considered the matter? If so what did you conclude? >Has anybody else given the matter any thought? >Gary > >----- Original Message ----- From: "Mike Borgelt" ><[email protected]> >To: "Discussion of issues relating to Soaring in Australia." ><[email protected]> >Sent: Friday, July 30, 2010 6:14 PM >Subject: Re: [Aus-soaring] Air vent > > >> >> >>When we were discussing the DG Mandl extractor air vent some time >>ago I think I mentioned that the best location would be on top of >>the fuselage in the low pressure area. >> >>It seems either somebody saw that or had the same idea. Blending the >>vent tangentially to the rear was always a good idea and is commonly >>used in engine cooling. Nice touch to add the louvre. This looks far >>better than the relatively crude DG vent. Might want to organise >>something so rain doesn't get in though. >> >>http://www.streckenflug.at/news/js_communication_2010_07.pdf >> >>Mike >>Borgelt Instruments - manufacturers of quality soaring instruments since 1978 >>phone Int'l + 61 746 355784 >>fax Int'l + 61 746 358796 >>cellphone Int'l + 61 428 355784 >> >>email: [email protected] >>website: www.borgeltinstruments.com >> >>_______________________________________________ >>Aus-soaring mailing list >>[email protected] >>To check or change subscription details, visit: >>http://lists.internode.on.net/mailman/listinfo/aus-soaring > > >-------------------------------------------------------------------------------- > > > >No virus found in this incoming message. >Checked by AVG - www.avg.com >Version: 9.0.851 / Virus Database: 271.1.1/3037 - Release Date: >07/30/10 04:34:00 > >_______________________________________________ >Aus-soaring mailing list >[email protected] >To check or change subscription details, visit: >http://lists.internode.on.net/mailman/listinfo/aus-soaring Borgelt Instruments - manufacturers of quality soaring instruments since 1978 phone Int'l + 61 746 355784 fax Int'l + 61 746 358796 cellphone Int'l + 61 428 355784 email: [email protected] website: www.borgeltinstruments.com _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
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