|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

12-20-2017, 05:13 PM
|
|
|
|
Join Date: Dec 2007
Location: Peachtree City, GA
Posts: 144
|
|
I guess it's time for Paul Harvey.....
"and now, the rest of the story"
As Dan (who has flow in my airplane) has stated, speed and energy management---I get it. I fly all three of the A320 models for my day job.
My request was for information, which the first reply provided, the rest of you just assumed you knew better. I promised when I first posted that I would include the good and the bad. Well, this is one of the issues that I've been searching for an answer to and its a two fold problem.
First,---The prototype engine I have runs at 2200RPM inflight- ALL THE TIME. The MTV-9 is set up to absorb all 230HP at approx. 2150 rpm statically. Think about that for a second..................... have you figured it out yet? Answer-- The static thrust is significant!  The Rv-10 is a slick airframe compared to the C182 that has used this type engine. When you compare my prop to the MTV-12, that any of you may be using, the blades are bigger. So slowing this thing down is more jet like. When power is reduced to idle, you coast for a while as the speed bleeds off. Planning is required for a stabilized approach.
Second----This is an air cooled diesel, if the CHTs get TOO COLD, the auto light function may not work and the pilot WILL start sweating. The lowest temps I've seen so far here in Georgia was 30F. It started first time using the glowplugs and didn't miss a beat inflight because the CHT never dropped below the min. inflight temp. Now, if you were flying in the high teens in MN in the winter and pulled it to idle and left it there--shock cooling may be the least of your worries.
The above two reasons are why I am interested in talking to someone who has installed the speedbrakes.
A little added drag in the pattern or when asked to expedite the descent by ATC would be a good thing. The production CD-265 is planned to operate at a different max rpm, so issue number one will be less of a problem. But the shock cooling and auto ignition will need to be watched.
I have flow this engine for 100 hours and have come to understand it. It's not a Lycoming- that's for certain. Even if my performance numbers don't eventually equal up to or exceed that of a 540 powered -10, that's fine with me.
I love the smell of Jet fuel in the morning. 
__________________
Scott Flandermeyer
Rv-10 TDI 300 hrs
Fayettevile, GA
2020 VAF Donation complete
|

12-20-2017, 07:25 PM
|
 |
|
|
Join Date: Nov 2010
Location: Okanagan Valley BC, Canada
Posts: 483
|
|
Had a set of Precise Flight brakes in the Mooney. At cruise power, popping the brakes would give me 1500fpm down right now... I would reduce that to about 1000fpm with trim for ear comfort...
Haven't missed them on the -8 except perhaps when coming into a formation a bit hot.
I realize you are considering other factors so I hope this helps...
__________________
Ron Townson
Okanagan Valley BC, Canada
RV-8 Completed Dec 2013
Membership renewed Sept 8, 2019
|

12-20-2017, 07:38 PM
|
 |
|
|
Join Date: Jan 2006
Location: New Smyrna Beach, FL
Posts: 1,339
|
|
Quote:
Originally Posted by Flandy10
"and now, the rest of the story"
As Dan (who has flow in my airplane) has stated, speed and energy management---I get it. I fly all three of the A320 models for my day job.
My request was for information, which the first reply provided, the rest of you just assumed you knew better. I promised when I first posted that I would include the good and the bad. Well, this is one of the issues that I've been searching for an answer to and its a two fold problem.
First,---The prototype engine I have runs at 2200RPM inflight- ALL THE TIME. The MTV-9 is set up to absorb all 230HP at approx. 2150 rpm statically. Think about that for a second..................... have you figured it out yet? Answer-- The static thrust is significant!  The Rv-10 is a slick airframe compared to the C182 that has used this type engine. When you compare my prop to the MTV-12, that any of you may be using, the blades are bigger. So slowing this thing down is more jet like. When power is reduced to idle, you coast for a while as the speed bleeds off. Planning is required for a stabilized approach.
Second----This is an air cooled diesel, if the CHTs get TOO COLD, the auto light function may not work and the pilot WILL start sweating. The lowest temps I've seen so far here in Georgia was 30F. It started first time using the glowplugs and didn't miss a beat inflight because the CHT never dropped below the min. inflight temp. Now, if you were flying in the high teens in MN in the winter and pulled it to idle and left it there--shock cooling may be the least of your worries.
The above two reasons are why I am interested in talking to someone who has installed the speedbrakes.
A little added drag in the pattern or when asked to expedite the descent by ATC would be a good thing. The production CD-265 is planned to operate at a different max rpm, so issue number one will be less of a problem. But the shock cooling and auto ignition will need to be watched.
I have flow this engine for 100 hours and have come to understand it. It's not a Lycoming- that's for certain. Even if my performance numbers don't eventually equal up to or exceed that of a 540 powered -10, that's fine with me.
I love the smell of Jet fuel in the morning. 
|
Well, now that you 'splain it that way...................................! An interesting and complex problem.
__________________
David Maib
RV-10 N380DM
New Smyrna Beach, FL
VAF Paid 1/21/2020
"In '69 I was 21, and I called the road my own"
Jackson Browne
|

12-21-2017, 06:48 AM
|
|
|
|
Join Date: Aug 2014
Location: Ocala, FL (Leeward Air Ranch)
Posts: 118
|
|
Another Experience
I have speed brakes on a Cessna P210, which adds about 500 fpm to descent rate or subtracts about 15 KT from level speed. As noted above, on a cleaner and lighter airframe such as a Mooney [or RV-10], speed brakes will provide more effect. When deployed they produce a rumble and vibration, enough to be noticed, but not to the point of disturbing passengers.
__________________
Bruce
Panther - Building 2019
RV-12 - Flying 2016; Sold 2018
RV-10 - Sold 2018; Flying 2018
SeaRey - Flying 2012; Sold 2017
|

12-21-2017, 02:00 PM
|
|
|
|
Join Date: Sep 2007
Location: Mesa Arizona
Posts: 608
|
|
It just seems to me that the holy grail of the impressive effort that you have put forth in this project is a CAFE level quest for efficiency and speed brakes to efficiency are like a mustache drawn on a masterpiece.
Have you considered cowl flaps that are restrictive in the closed position or adjustable (butterfly?) intake air?
__________________
Myron Nelson
Mesa, AZ
RV-10 N24EV
KITPLANES Contributing Editor
|

12-21-2017, 02:36 PM
|
 |
|
|
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 9,035
|
|
Quote:
Originally Posted by Flandy10
"and now, the rest of the story"
As Dan (who has flow in my airplane) has stated, speed and energy management---I get it. I fly all three of the A320 models for my day job.
My request was for information, which the first reply provided, the rest of you just assumed you knew better. I promised when I first posted that I would include the good and the bad. Well, this is one of the issues that I've been searching for an answer to and its a two fold problem.
First,---The prototype engine I have runs at 2200RPM inflight- ALL THE TIME. The MTV-9 is set up to absorb all 230HP at approx. 2150 rpm statically. Think about that for a second..................... have you figured it out yet? Answer-- The static thrust is significant!  The Rv-10 is a slick airframe compared to the C182 that has used this type engine. When you compare my prop to the MTV-12, that any of you may be using, the blades are bigger. So slowing this thing down is more jet like. When power is reduced to idle, you coast for a while as the speed bleeds off. Planning is required for a stabilized approach.
Second----This is an air cooled diesel, if the CHTs get TOO COLD, the auto light function may not work and the pilot WILL start sweating. The lowest temps I've seen so far here in Georgia was 30F. It started first time using the glowplugs and didn't miss a beat inflight because the CHT never dropped below the min. inflight temp. Now, if you were flying in the high teens in MN in the winter and pulled it to idle and left it there--shock cooling may be the least of your worries.
The above two reasons are why I am interested in talking to someone who has installed the speedbrakes.
A little added drag in the pattern or when asked to expedite the descent by ATC would be a good thing. The production CD-265 is planned to operate at a different max rpm, so issue number one will be less of a problem. But the shock cooling and auto ignition will need to be watched.
I have flow this engine for 100 hours and have come to understand it. It's not a Lycoming- that's for certain. Even if my performance numbers don't eventually equal up to or exceed that of a 540 powered -10, that's fine with me.
I love the smell of Jet fuel in the morning. 
|
I am wondering to myself if a custom designed belly board wouldn't be a better option than speed brakes.
Depending on its design it could be more variable than the all or nothing speed brakes, which might make it more useful for your situation, but not sure.....
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.
Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
|

12-21-2017, 02:50 PM
|
|
Super Moderator
|
|
Join Date: May 2005
Location: Locust Grove, GA
Posts: 2,627
|
|
I was wondering that controlling the air inlets might be easier and less draggy. I'm not an aeronautical engineer and I didn't stay at a Holiday Inn last night, though. 
__________________
 Vic Syracuse
Built RV-4, RV-6, 2-RV-10's, RV-7A, RV-8, Prescott Pusher, Kitfox Model II, Kitfox Speedster, Kitfox 7 Super Sport, Just Superstol, DAR, A&P/IA, EAA Tech Counselor/Flight Advisor, CFII-ASMEL/ASES
Kitplanes "Unairworthy" monthly feature
EAA Sport Aviation "Checkpoints" column
EAA Homebuilt Council Chair/member EAA BOD
Author "Pre-Buy Guide for Amateur-Built Aircraft"
www.Baselegaviation.com
|

12-21-2017, 03:58 PM
|
 |
|
|
Join Date: May 2006
Location: Houston
Posts: 2,012
|
|
Be prepared for spontaneous human combustion and instant death!
__________________
Bryan
Houston
Last edited by Low Pass : 12-21-2017 at 04:02 PM.
|

12-21-2017, 08:40 PM
|
|
|
|
Join Date: Dec 2007
Location: Peachtree City, GA
Posts: 144
|
|
Rodrigo, Ron and Bruce- Thanks, that is the type of info I wanted.
While speedbrakes may not be an artistic solution, they are a readily available option that would accommodate both issues. The cowling now includes a set of cowl flaps that I use every flight and I am working on "shrinking the exit" to keep the temperatures in the desired range during all phases of flight.
I have also considered, as Scott mentioned, a "belly board" similar to the SBD dive brakes. Still contemplating the structural and operational implementation of that idea.
This project is constantly evolving and there are days I wish I was an areo engineer who stayed at a Holiday Inn Express. I can truly say that this project has been an education.
__________________
Scott Flandermeyer
Rv-10 TDI 300 hrs
Fayettevile, GA
2020 VAF Donation complete
|

12-22-2017, 05:45 AM
|
|
|
|
Join Date: Aug 2014
Location: Ocala, FL (Leeward Air Ranch)
Posts: 118
|
|
Long EZ Speed Brake
Some Long EZs have a belly air brake. See: http://www.aryjglantz.com/2013/08/ch...-overview.html for some starter ideas.
__________________
Bruce
Panther - Building 2019
RV-12 - Flying 2016; Sold 2018
RV-10 - Sold 2018; Flying 2018
SeaRey - Flying 2012; Sold 2017
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 07:32 AM.
|