Honda 1.8L running on test stand video

[charosenz]

Folks,

I have not firm up the exact inlet and outlet dimensions. The main difference between Ross' set up and what I am dealing with is the center section of my cowling bottom does extend down below the fuse belly some. Right now I am looking at 4"H x 18" inlet which I know is a lot more than what Ross recommends. But....about 40% is covered by the cowling belly. I will need to stay at the 18" width of the inlet due to the bottom cowling bump, but Ross' research and experience gives me encouragement that I should be able to get the height of the inlet down to 3" or so. I will create another cardboard mock up soon.

[DanH]

Originally Posted by charosenz

I have not firm up the exact inlet and outlet dimensions. The main difference between Ross' set up and what I am dealing with is the center section of my cowling bottom does extend down below the fuse belly some. Right now I am looking at 4"H x 18" inlet which I know is a lot more than what Ross recommends. But....about 40% is covered by the cowling belly. I will need to stay at the 18" width of the inlet due to the bottom cowling bump, but Ross' research and experience gives me encouragement that I should be able to get the height of the inlet down to 3" or so. I will create another cardboard mock up soon.

Adding frontal area because you already added frontal area? Brother Charlie, think outside The Box.

If the center of the cowl hangs low, perhaps you could use two inlets, one on each side of the hanging cowl section.

Perhaps two inlets and two exits....two separate ducts systems. The narrowed width of each heat exchanger could proportionally shorten the inlet and exit diffusers. Conceptually it would be a little like the underwing exchangers, except being inboard on the fuselage, you are not so constrained in overall length. And I'd try to move them rearward some. You want the inlet in a high pressure area and the exit in a low pressure area.

There is also an aesthetic aspect. None of this need look like a wheelbarrow.

http://www.vansairforce.com/communit...&postcount=129

[charosenz]

Dan,

I honestly don't know what causes you to feel the need to ridicule and nitpick my project - calling it a wheel barrow. I can think of many reasons what causes this behavior but I am not a psychiatrist.

It is rude and most important it is unwanted. I have asked you to stop and even others have asked you to stop. Yet it continues.

I have already had a moderator delete one of your post hoping you would get the hint.

There are too many good people who for reasons of their own, are interested in my project and your unwelcome parental behavior stinks. So regardless of your reasons - stop.

Charlie

[charosenz]

I thought it might be help or of interest at least to most people, what the cowl bump and its relation to the belly inlet looked like so here is a pic.

Notice on the cardboard template there is a line at the bottom marking where a 3"height would take the inlet as compared to the template itself which is 4". Based on Ross' real world experience I am leaning towards making it 3".

[charosenz]

Here is a pic of the radiator submersed in water where I pressurized it to 15 lbs. It passed with no bubbles.

[DanH]

Originally Posted by charosenz

I honestly don't know what causes you to feel the need to ridicule and nitpick my project - calling it a wheel barrow.

Put that chip back in your pocket Charlie. You asked for comments. It's unreasonable to expect nothing but "Wow, that's great!"

I've been dead serious. The proposed inlet and exit areas are excessive, throttling the inlet would be a technical error, the additional frontal area adds external drag, and it's not going to be pretty. I don't believe in being critical without proposing solutions, so I've linked photos of other liquid cooled aircraft, proposed ideas, and explored details. You're under no obligation to consider any of these things, but they are legitimate commentary.

[rv6ejguy]

On the inlet sizing question, assuming you have the rest of the duct/ diffuser shape and rad sizing correct, experiments by Russell Sherwood have shown that he can cool 230hp with less than 15 square inches of inlet area. He said he'd go down to 12.5 if there was another iteration in the future. It does look like ground cooling is impacted somewhat by reducing the inlet size so be careful there.

On my installation, the main rad inlet is a lot bigger than that primarily because I couldn't get my hand and wrench in to access the bolts which attach the splitter to the rad and would have had great difficulty in laying in the glass and resin if it had been smaller. As you shrink the inlet, the diffuser shape and guide vane placement become more critical to make it all work efficiently so that is a consideration too.

The penalty of a slightly oversize inlet is minimal from what we know as long as you can throttle the exit.

This all being said, none of us want to re-do a rad scoop design which doesn't cool adequately in the climb or on the ground so we tend to fudge the rad and inlet sizes upwards.

[charosenz]

[quote=DanH;1335924]Put that chip back in your pocket Charlie. You asked for comments. It's unreasonable to expect nothing but "Wow, that's greaD

Dan,. You missed it completely. Your parental dismissive comments are unwelcome.

I have always welcome constructive comments that are respectful. And when they come from some one who has real world experience like Ross, it has value. When it comes from someone who works at putting others down to make themselves (think they) sound smart it's arrogance. Stop it. Move on to somewhere else.

[charosenz]

Originally Posted by rv6ejguy

On the inlet sizing question, assuming you have the rest of the duct/ diffuser shape and rad sizing correct, experiments by Russell Sherwood have shown that he can cool 230hp with less than 15 square inches of inlet area. He said he'd go down to 12.5 if there was another iteration in the future. It does look like ground cooling is impacted somewhat by reducing the inlet size so be careful there.

On my installation, the main rad inlet is a lot bigger than that primarily because I couldn't get my hand and wrench in to access the bolts which attach the splitter to the rad and would have had great difficulty in laying in the glass and resin if it had been smaller. As you shrink the inlet, the diffuser shape and guide vane placement become more critical to make it all work efficiently so that is a consideration too.

The penalty of a slightly oversize inlet is minimal from what we know as long as you can throttle the exit.

This all being said, none of us want to re-do a rad scoop design which doesn't cool adequately in the climb or on the ground so we tend to fudge the rad and inlet sizes upwards.

Ross the real world experience and research is super helpful. I am incorporating these concepts (generally) in my design. I'm still in the cardboard template stage. The radiator will be at or larger than yours, even though I will be at lower HP.

In case some folks have not noticed I'm not driven to win style points and while I appreciate and value learning from others who have actual been there experience, I,'m also not driven to spend lots hours to achieve perfect efficiency. Others who have gone before me like you and Dave Anders, my hats off to you!. And thank you very much for sharing your lessons leard.

My scoop will be aluminum sheet. It's what I'm comfortable working with. It will be simple. It will be attached by screws and easily removable if needed.

It won't be perfect. It will work well. I'll continue to share my progress as long as there is interest.

Charlie.

[DanH]

Originally Posted by charosenz

Put that chip back in your pocket Charlie. You asked for comments. It's unreasonable to expect nothing but "Wow, that's great"

Dan,. You missed it completely. Your parental dismissive comments are unwelcome.

You're under no obligation to consider them, but they remain legitimate commentary...and not written for you alone.

Stop it. Move on to somewhere else.

Request declined. You post as you wish, as will I, both within a reasonable interpretation of the VAF rules. Please note that personal comments are generally not acceptable.