Laminar Flow Titanium Windscreen

Come check out a compilation of Zelph's stove designs.
Post Reply
User avatar
zelph
Posts: 15834
Joined: Tue Aug 14, 2007 1:53 pm

Laminar Flow Titanium Windscreen

Post by zelph » Sat Dec 22, 2012 8:31 pm



In nonscientific terms laminar flow is "smooth", while turbulent flow is "rough".

the transition from laminar flow to turbulence can be sensitive to disturbance levels and imperfections present in a given configuration.

Insufficient holes in a windscreen causes turbulance. Even though my EZ Fold windscreens have at least 4 times as many holes as those in competitors screens we still observe turbulance.

The above video was created in 2009. Since then I've designed a Titanium windscreen that eliminates most of the turbulance. The design is nothing I've seen so far by others. I just wanted everyone to review the video befor I show my new creation. "The Laminar Flow Windscreen" The dimensions used on the screen are critical to achieve the laminar flow. Once you see the design you'll understand why I used titanium to make it.

Some of you are going to say laminar flow is for water only. We want to use the word laminar flow in a general way. Like I said above, in nonscientific terms ;) go easy on me :D
http://www.woodgaz-stove.com/

User avatar
cadyak
Posts: 452
Joined: Mon Dec 14, 2009 5:53 pm
Location: albany,ga

Re: Laminar Flow Titanium Windscreen

Post by cadyak » Sat Dec 22, 2012 11:46 pm

I remember this video. It really shows how much the flame is effected by the turbulence.
Most of the time when I use a windscreen, It is one from my woodstoves which doesnt have any holes at all. When I use the windscreen with an alcohol stove I prop the windscreen up on small twigs so that the air passes underneath it as it does in your video.

User avatar
zelph
Posts: 15834
Joined: Tue Aug 14, 2007 1:53 pm

Re: Laminar Flow Titanium Windscreen

Post by zelph » Sun Dec 23, 2012 1:14 am

I remember this video. It really shows how much the flame is effected by the turbulence.
Yeah, I was amazed how much turbulance was present with the windscreen around the stove. The same thing occured when I punched 1/2" holes all the way around the windscreen. Holes create jets of turbulance. The StarLyte is 2" in diameter and that's a lot of surface evaporating large amounts of gas to be ignited. Once ignited it wants to burn at a fast rate, use lots of oxygen so it's got to come in from somewhere. If it can't get enough from the bottom it comes in over the top of the windscreen. If the windscreen is too close to the pot it will prevent enough air getting to the stove and reduce the flame output and burn inefficiently.
http://www.woodgaz-stove.com/

User avatar
zelph
Posts: 15834
Joined: Tue Aug 14, 2007 1:53 pm

Re: Laminar Flow Titanium Windscreen

Post by zelph » Mon Dec 24, 2012 7:45 pm

This what the first prototype looked like. That's a 2 cup Ridgeline Foster pot next to it for height/size comparison.

The windscreen will store inside or outside of a Foster Pot. If it is wrapped around the outside, the pot will have maximum protection while being stored.

I should have a video made of the kit by the end of the week. This is the busiest week of the year for me. :o
Attachments
cabbage head 010.jpg
http://www.woodgaz-stove.com/

User avatar
zelph
Posts: 15834
Joined: Tue Aug 14, 2007 1:53 pm

Re: Laminar Flow Titanium Windscreen

Post by zelph » Thu Dec 27, 2012 12:28 am

geeehsh! can't find time to do a video :roll:
http://www.woodgaz-stove.com/

User avatar
zelph
Posts: 15834
Joined: Tue Aug 14, 2007 1:53 pm

Re: Laminar Flow Titanium Windscreen

Post by zelph » Sat Jan 12, 2013 8:32 pm

This project is interesting. Working with Ti is a whole new world. This windscreen is going to be dual purpose. Holy Moly, can you imagine that. It will be a wood burner of the most awesome kind. You'll be able to burn esbit in it also, can you believe that!!! And last but not least, you can burn alcohol in it. Now that is one heck of a multipurpose windscreen :D I've been conducting burn tests with it and I'm learning a lot how Ti responds to high heat. It wants to warp out of it's circular shape. Have no fear, I've discovered a way to tame it down. After burning wood in it, we'll want to burn some alcohol so we want the windscreen to be round in it's shape to have an even flow of heat around the pot. I'm using a Fosters' flat bottom can as the pot, sure why not i make them ;) Ti is strong enough to hold larger pots that will hold 4 cups of water without any problems. Better yet it will probably hold half gallon easy. :o

The windscreen/potsupport right now is about 22 grams. 0.07 ounce.

For those who might be interested, the shape of the windscreen is not "cone" :)
http://www.woodgaz-stove.com/

FireTamer
Posts: 78
Joined: Thu Dec 06, 2012 6:35 pm

Re: Laminar Flow Titanium Windscreen

Post by FireTamer » Thu Jan 17, 2013 12:36 pm

I noticed after some testing my Companion burners that they were doing the same thing. I just figured it was one of the characteristics of the burner. Then one day I took one of them outside to do some testing. After getting everything set up I realized that I had left the windscreen(holes in bottom) inside of the house. Being lazy, I grabbed one of my metal chicken feeders, popped off the bottom pan, then set it around the burner. To allow air to get to the burner I placed 1/2" sticks under it to allow air to flow to the burner. After firing up the burner I noticed that it burned very calmly. No flickering or dancing at all. And all this time I thought it was lack of oxygen(after the fact). I have been raising the windscreens instead of punching them ever since. LOL...learn something everyday! Laminar Flow...who wudda thunk it?

FT

User avatar
zelph
Posts: 15834
Joined: Tue Aug 14, 2007 1:53 pm

Re: Laminar Flow Titanium Windscreen

Post by zelph » Thu Jan 17, 2013 4:20 pm

Yes, it's interesting how we learn things...by doing ;)

When I first created the 6" tall EZ-Fold windscreen with so many holes in it I noticed that when I surrounded a stove with it the flames were jumping all over the place. Curiosity told me to raise it slowly to see what happens. low and behold....laminar flow is created. I created laminar flow :lol: It's one of those moments when a light goes on :idea: So time passes and I decide to work with Titanium for a windscreen, make something special :o
http://www.woodgaz-stove.com/

User avatar
zelph
Posts: 15834
Joined: Tue Aug 14, 2007 1:53 pm

Re: Laminar Flow Titanium Windscreen

Post by zelph » Thu Jan 17, 2013 9:42 pm

Here is a video that I did today to show the diference between 2 different hole paterns in the windscreen. The one has 1/2" dia. holes and the other one is the new design that I'll be using with the titanium windscreens.



Just think how turbulant the flames would be if I have 1/4" holes at the base.
http://www.woodgaz-stove.com/

User avatar
cadyak
Posts: 452
Joined: Mon Dec 14, 2009 5:53 pm
Location: albany,ga

Re: Laminar Flow Titanium Windscreen

Post by cadyak » Fri Jan 18, 2013 1:39 am

great video. :D

Post Reply