---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Tue 10/02/07: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:43 AM - Re: Jab cooling (Graham Singleton) 2. 11:41 AM - Re: Constant Speed newbie question (steve v) 3. 02:19 PM - Re: Jab cooling (Gilles Thesee) 4. 02:23 PM - Re: Jab cooling (Gilles Thesee) 5. 05:08 PM - Re: Jab cooling (Mike Gregory) ________________________________ Message 1 _____________________________________ Time: 02:43:35 AM PST US From: Graham Singleton Subject: Re: Europa-List: Jab cooling John thanks for your fascinating test results. I too am very puzzled by the apparent lack of effectiveness of Pressure. Air will only move from hi P to Low P, (apart from Coriolis effects of course, witness circulation round cyclones) I wonder if your turbulator is helping keep the flow attached over the whole of the outside of the cowl? That might reduce the pressure around the outlet at the back and that is what is important as we all know but can't quite understand (how to make it better I mean) In flight the flow over the cowl will be quite assymetric Thoughts Gilles? Graham TELEDYNMCS@aol.com wrote: > In a message dated 10/1/2007 2:58:40 AM Eastern Daylight Time, > europa-list@matronics.com writes: > > /Concerning the Jabiru, there is little room between the prop and the > front cylinders to provide a correct diffuser, so the inlet must be of > larger size, and the efficiency will be lower. > But the engine can be adequately cooled all the same, at the price of a > little more drag, of course./ > > > Hi Gilles and all, > > I've had a chance to test my turbulators installed at the mouth of my > left cooling intake and they worked exceedingly well. I've seen, on > average, a 25F drop in CHT's on the left side now that I have turbulated > the airflow entering the left side intake. > > The moral of this story is: for better /FLOW/, excite the area just > outside the hole. Almost pornographic, isn't it? (notice how I didn't > say for better /PRESSURE/?) > > Now, I'm back to analysis of boundary flow on the wings....... > > Regards, > > John Lawton > Whitwell, TN (TN89) > N245E - Flying > ________________________________ Message 2 _____________________________________ Time: 11:41:02 AM PST US Subject: Re: Europa-List: Constant Speed newbie question From: "steve v " OK, Thanks, 35 it is then! Steve Vestuti #573 Visit - www.EuropaOwners.org ________________________________ Message 3 _____________________________________ Time: 02:19:25 PM PST US From: Gilles Thesee Subject: Re: Europa-List: Jab cooling Graham Singleton a crit : > Your english is as good as mine! Wish my french was half as good {{:-( Graham, Blushing with embarrassment ;-) Thank you for your kind message. I already updated the English version of the Cowling slideshows. Any corrections concerning style, spelling, grammar, etc. are welcome. Best regards, -- Gilles http://contrails.free.fr ________________________________ Message 4 _____________________________________ Time: 02:23:13 PM PST US From: Gilles Thesee Subject: Re: Europa-List: Jab cooling > I wonder if your turbulator is helping keep the flow attached over the > whole of the outside of the cowl? That might reduce the pressure > around the outlet at the back and that is what is important as we all > know but can't quite understand (how to make it better I mean) > In flight the flow over the cowl will be quite assymetric > Thoughts Gilles? Graham, John and all, A little busy at the moment, so I may have missed some detail on John's setup. I'm naturally much interested in any successful engine installation. John, did you provide a link to your engine installation ? Sorry if I missed the obvious. Please continue to give info, Best regards, -- Gilles http://contrails.free.fr ________________________________ Message 5 _____________________________________ Time: 05:08:44 PM PST US From: "Mike Gregory" Subject: RE: Europa-List: Jab cooling I recall that in 1995 I asked the late Richard Cabrinha why he had changed from a chin intake to a pair of Lo-Presti style circular intakes on his Free Spirit Mark II, for cooling a Continental IO 360, and he replied "because they work!" He told me that if the diameter were too large then there would be a reverse flow, spilling air out round the circumference of each intake. He refined the size by putting some oil around each rim and doing a quick circuit: inspection on landing showed whether the oil film had spread inwards or migrated outwards, and he would then the repeat the test with different diameters accordingly. For those on HTML, here is a picture of the final result: It may not have been the most scientific way of finding the right size, but he claimed that it worked. I have no information on the distribution of air and temperature levels for the six cylinders. He did however incorporate cowl flaps, one on each side at the rear of the cowling (the starboard one is visible in the picture), which he said he would like to eliminate in due course to simplify the design with a fixed outlet area. Best regards Mike -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of Gilles Thesee Sent: 02 October 2007 22:22 Subject: Re: Europa-List: Jab cooling > I wonder if your turbulator is helping keep the flow attached over the > whole of the outside of the cowl? That might reduce the pressure > around the outlet at the back and that is what is important as we all > know but can't quite understand (how to make it better I mean) > In flight the flow over the cowl will be quite assymetric > Thoughts Gilles? Graham, John and all, A little busy at the moment, so I may have missed some detail on John's setup. I'm naturally much interested in any successful engine installation. John, did you provide a link to your engine installation ? Sorry if I missed the obvious. Please continue to give info, Best regards, -- Gilles http://contrails.free.fr ------------------------------------------------------------------------------------- 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.