PDA

View Full Version : Prop Pitch and Radiator Settings: Newbie Questions.



XyZspineZyX
08-22-2003, 04:58 AM
So talk to me about 'prop pitch' and 'radiator settings'.


My basic assumptions:

Radiator settings:
Closed> Lower drag, but also less heat dissipation.
Open> Most drag, but heat dissipates the fastest.


Prop Pitch:
100%> Blades are nearly 'vertical', more efficient at high speeds.

50%> Blades are more 'horizontal', more efficient at lower speeds.


This is my first 'real' flightsim. I love flying the I153 (or whatever the Russian biplane is), but I seem to have problems getting the most out of my engine. Should I be matching prop-pitch to engine power? Should the radiator stay open unless I need the extra airspeed?

Thanks in advance!

XyZspineZyX
08-22-2003, 04:58 AM
So talk to me about 'prop pitch' and 'radiator settings'.


My basic assumptions:

Radiator settings:
Closed> Lower drag, but also less heat dissipation.
Open> Most drag, but heat dissipates the fastest.


Prop Pitch:
100%> Blades are nearly 'vertical', more efficient at high speeds.

50%> Blades are more 'horizontal', more efficient at lower speeds.


This is my first 'real' flightsim. I love flying the I153 (or whatever the Russian biplane is), but I seem to have problems getting the most out of my engine. Should I be matching prop-pitch to engine power? Should the radiator stay open unless I need the extra airspeed?

Thanks in advance!

XyZspineZyX
08-22-2003, 06:02 AM
Actualy 100% prop pich is like first gear in a car. Or it better yet, it is like the propeler on a boat engin.

You start off with 100% but you decreas it as you excellerate. If you dont decreas the prop pitch you will blow the engine. You have to wach your rpm, find out what the combat rpm is and dont exseed it.

I tride using manule prop pich on the P-47 and the P-40 and it dosent work, for some reason Oleg figured they didn't need it. You can use prop pitch to slow down in a hury, use 0% prop pitch.

From what someone told me, i think it was BuzzU; only the German plane's use manule prop pitch. I have tride a couple of BF109's and manule prop pitch dose work on them.

Any way there are other people who can better explane this.



Have fun and good luck.

XyZspineZyX
08-22-2003, 06:13 AM
In 109's try and keep your RPMs between 2500-3000. For other planes it varies but I usually keep it on 100% pitch in combat but when cruising to and from battle I keep it lower, it saves fuel.

<img src="http://www.geocities.com/agrill101/Sig.jpg.txt"

XyZspineZyX
08-22-2003, 07:59 AM
I sure wish you could set a mission on autopilot, sit back and watch what prop, mix and radiator setting changes are made during various maneuvers. Looking at the gauges is not good enough, since you can't see what the plane is doing. I'd like to watch a mission from external view and be alerted by the screen text that normally shows during manual control. A few of those examples and I could get a better idea of what's going on and use complex engine management with more confidence.

michapma
08-22-2003, 08:09 AM
For radiators, it is something like that. There is no special need to fly with the radiator open in normal flight, but if you need to quickly cool your engine or you are recovering from or preparing for combat then use it. Yes, flying with the radiator flaps open or partially open keeps the engine cooler. Keep in mind that German planes have an automatic setting. Something you may have overlooked is that those radiator flaps provide protection for the critical oil coolant system on aircraft that have it, and extra protection for air-cooled engines. Close radiator flaps when you are engaging the enemy or being fired upon by AAA.

Prop pitch does NOT work JUST like gears in a car. I consider it a faulty analogy. If full fine prop pitch is like first gear in a car, do you put your car in first gear when you are going full speed down the highway? It is true that the propeller can load and unload the engine just like gears on a car. However, prop pitch is more analagous to being able to change the kinds of tires you have on your car, which is not possible.

Most of the aircraft have governors that change prop pitch in order to keep the rpm in a selected range. Most Russian, British and US planes have constant speed propellers that work this way. German aircraft systems work somewhat differently, so let us know if that's what you're looking for, although you can usually leave them on automatic.

The 100% setting for most aircraft (with the constant speed propellers) is the same as setting the governor to maintain full RPM, just at the redline. This is the rpm region where the engine can develop maximum torque, thus resulting in maximum power. Reducing the % setting tells the engine to back off the rpms. You get less power and in most cases better fuel economy. In this sense it is like shifting into a higher gear in a car to run at a lower rpm. The difference to a car is that in a car you can't set the rpms directly.

Hope that helps,
Mike

<table width="100%" border="0" cellspacing="0" cellpadding="10"><tr valign="middle" bgcolor="#3e463b"><td height="40" colspan="3" align="center">The ongoing IL-2 User's Guide project (http://people.ee.ethz.ch/~chapman/il2guide/)</a></td></tr><tr bgcolor="#515e2f"><td width="40%">FB engine management:
Manifold Pressure sucks (http://www.avweb.com/news/columns/182081-1.html)
Those Marvelous Props (http://www.avweb.com/news/columns/182082-1.html)
Mixture Magic (http://www.avweb.com/news/columns/182084-1.html)
Putting It All Together (http://www.avweb.com/news/columns/182085-1.html)
Those Fire-Breathing Turbos (Part 1 of 6) (http://www.avweb.com/news/columns/182102-1.html)</td><td align="center">

‚ =69.GIAP=Chap‚

69.GIAP (http://www.baseclass.modulweb.dk/giap/)</p></td><td width="40%" align="right" valign="top">Hardware:
Flight Simulation Performance Analyzed (http://www.simhq.com/_air/air_062a.html)
Building a home-made throttle quadrant step by step (http://forums.ubi.com/messages/message_view-topic.asp?name=us_il2sturmovik_gd&id=zkavv)
Sound Can Be Hazardous for Games (http://www6.tomshardware.com/game/20030405/index.html)</td></tr></table>

michapma
08-22-2003, 08:37 AM
"Mr. Burns" /i/smilies/16x16_robot-wink.gif

This would do you little good, since on autopilot your engine management is greatly simplified. For instance, when on autopilot your engine will not heat up. You'll never see the AI change the prop settings. In fact the other day I was cruising in an I-16 with the rpm control set at 80%. (Normally I choose 60 or 70% for better economy, but needed more power to keep up. Optimal fuel economy setting is determined by rpm and manifold pressure, and you can get the suggest rpm rating for this from the AdvancedPDFmanual document on CD 2.) To speed up the mission (I got impatient and IIRC I was repeating the mission) I hit autopilot. He had trouble keeping up like he normally does, and I noticed that the rpms were staying down around the value corresponding to 80%. I exited autopilot, reset prop/rpm setting, and reengaged, and it did fine. The AI seems unaware of the prop system.

Better would be to find some tracks where people use CEM in the context you'd like to use it. Then you can see in the HUD what they did.

Mike

<table width="100%" border="0" cellspacing="0" cellpadding="10"><tr valign="middle" bgcolor="#3e463b"><td height="40" colspan="3" align="center">The ongoing IL-2 User's Guide project (http://people.ee.ethz.ch/~chapman/il2guide/)</a></td></tr><tr bgcolor="#515e2f"><td width="40%">FB engine management:
Manifold Pressure sucks (http://www.avweb.com/news/columns/182081-1.html)
Those Marvelous Props (http://www.avweb.com/news/columns/182082-1.html)
Mixture Magic (http://www.avweb.com/news/columns/182084-1.html)
Putting It All Together (http://www.avweb.com/news/columns/182085-1.html)
Those Fire-Breathing Turbos (Part 1 of 6) (http://www.avweb.com/news/columns/182102-1.html)</td><td align="center">

‚ =69.GIAP=Chap‚

69.GIAP (http://www.baseclass.modulweb.dk/giap/)</p></td><td width="40%" align="right" valign="top">Hardware:
Flight Simulation Performance Analyzed (http://www.simhq.com/_air/air_062a.html)
Building a home-made throttle quadrant step by step (http://forums.ubi.com/messages/message_view-topic.asp?name=us_il2sturmovik_gd&id=zkavv)
Sound Can Be Hazardous for Games (http://www6.tomshardware.com/game/20030405/index.html)</td></tr></table>

michapma
08-22-2003, 09:21 AM
Actually FlightVector made a post that I just ran across that made me pause about the advice I just gave:

http://forums.ubi.com/messages/message_view-topic.asp?name=us_il2sturmovik_gd&id=zamhs

Now I'm not 100% sure whether 100% "prop-pitch" setting (full rpm) gives max thrust for full speed. Reducing rpm somewhat to get an engine into its proper power band makes sense, it seems to be a question of whether max torque is developed at full rpm (redline) and how efficient the prop is at coarser settings. (I would guess still pretty efficient.)

Cheers,
Mike

<table width="100%" border="0" cellspacing="0" cellpadding="10"><tr valign="middle" bgcolor="#3e463b"><td height="40" colspan="3" align="center">The ongoing IL-2 User's Guide project (http://people.ee.ethz.ch/~chapman/il2guide/)</a></td></tr><tr bgcolor="#515e2f"><td width="40%">FB engine management:
Manifold Pressure sucks (http://www.avweb.com/news/columns/182081-1.html)
Those Marvelous Props (http://www.avweb.com/news/columns/182082-1.html)
Mixture Magic (http://www.avweb.com/news/columns/182084-1.html)
Putting It All Together (http://www.avweb.com/news/columns/182085-1.html)
Those Fire-Breathing Turbos (Part 1 of 6) (http://www.avweb.com/news/columns/182102-1.html)</td><td align="center">

‚ =69.GIAP=Chap‚

69.GIAP (http://www.baseclass.modulweb.dk/giap/)</p></td><td width="40%" align="right" valign="top">Hardware:
Flight Simulation Performance Analyzed (http://www.simhq.com/_air/air_062a.html)
Building a home-made throttle quadrant step by step (http://forums.ubi.com/messages/message_view-topic.asp?name=us_il2sturmovik_gd&id=zkavv)
Sound Can Be Hazardous for Games (http://www6.tomshardware.com/game/20030405/index.html)</td></tr></table>

XyZspineZyX
08-22-2003, 12:14 PM
VF_310thSilent wrote:
- I tride using manule prop pich on the P-47 and the
- P-40 and it dosent work, for some reason Oleg
- figured they didn't need it. You can use prop pitch
- to slow down in a hury, use 0% prop pitch.


Actually pitch does work on those planes. If you put your throttle at about 75-85 % and your pitch at say 80% you will be aazed at how much speed you will pick up...especially in a Jug. It will be slow but the speed will steadily increase..try it.

<CENTER>http://www.world-wide-net.com/tuskegeeairmen/ta-1943.jpg <marquee><FONT COLOR="RED"><FONT SIZE="+1">"Straighten up.......Fly right..~S~"<FONT SIZE> </marquee> http://www.geocities.com/rt_bearcat

<CENTER><FONT COLOR="ORANGE">vflyer@comcast.net<FONT COLOR>
<Center><div style="width:200;color:red;font-size:18pt;filter:shadow Blur[color=red,strength=8)">99th Pursuit Squadron

michapma
08-22-2003, 01:06 PM
That's odd... throttle back to go faster?

<table width="100%" border="0" cellspacing="0" cellpadding="10"><tr valign="middle" bgcolor="#3e463b"><td height="40" colspan="3" align="center">The ongoing IL-2 User's Guide project (http://people.ee.ethz.ch/~chapman/il2guide/)</a></td></tr><tr bgcolor="#515e2f"><td width="40%">FB engine management:
Manifold Pressure sucks (http://www.avweb.com/news/columns/182081-1.html)
Those Marvelous Props (http://www.avweb.com/news/columns/182082-1.html)
Mixture Magic (http://www.avweb.com/news/columns/182084-1.html)
Putting It All Together (http://www.avweb.com/news/columns/182085-1.html)
Those Fire-Breathing Turbos (Part 1 of 6) (http://www.avweb.com/news/columns/182102-1.html)</td><td align="center">

‚ =69.GIAP=Chap‚

69.GIAP (http://www.baseclass.modulweb.dk/giap/)</p></td><td width="40%" align="right" valign="top">Hardware:
Flight Simulation Performance Analyzed (http://www.simhq.com/_air/air_062a.html)
Building a home-made throttle quadrant step by step (http://forums.ubi.com/messages/message_view-topic.asp?name=us_il2sturmovik_gd&id=zkavv)
Sound Can Be Hazardous for Games (http://www6.tomshardware.com/game/20030405/index.html)</td></tr></table>

XyZspineZyX
08-22-2003, 03:25 PM
Bearcat99 wrote:
-
- VF_310thSilent wrote:
-- I tride using manule prop pich on the P-47 and the
-- P-40 and it dosent work, for some reason Oleg
-- figured they didn't need it. You can use prop pitch
-- to slow down in a hury, use 0% prop pitch.
-
-
- Actually pitch does work on those planes. If you put
- your throttle at about 75-85 % and your pitch at say
- 80% you will be aazed at how much speed you will
- pick up...especially in a Jug. It will be slow but
- the speed will steadily increase..try it.
-
- <CENTER><img
- src="http://www.world-wide-net.com/tuskegeeairmen/
- ta-1943.jpg"><marquee><FONT COLOR="RED"><FONT
- SIZE="+1">"Straighten up.......Fly right..~S~"<FONT
- SIZE> </marquee> <a
- href="http://www.geocities.com/rt_bearcat"
- target=_blank>http://www.geocities.com/rt_bearcat<
- /a>


Like i said before, i tride that three times, I spent a total 1:45 min and nothing, oops no not nothing actual by deceasing the prop pitch on the Jug my speed dropped.

I no, you said wait a couple of min. I waited about 3 full min and nothing happend. I decreased and decrease and my speed went down and down.

What i am saying is that are you shure it was the Jug you were flying. So far BuzzU has been correct about prop pitch not working the way it should on some of the planes.



Message Edited on 08/22/0302:27PM by VF_310thSilent

XyZspineZyX
08-22-2003, 04:20 PM
There is some incorrect information in this thread Otto, be careful what you take as fact. To clarify, you should determine whether the aircraft you are flying has a Constant Speed Prop (such as FW190 or La5FN), or a Variable Speed Prop (such as Bf109), or a Fixed Prop (such as TB-3 bomber). Assuming your flying the I153, I believe it has a constant speed prop (CSP).

CSP's are the most common (and modern) prop type, and are simple in operation. They develope the most power, most speed, and use the most fuel, at 100%, which actually means maximum engine RPM (nothing to do with prop pitch) as seen on the cockpit guage (max horsepower output, torque/acceleration may be a different story). The prop adjusts itself to your airspeed to maintain that selected RPM (Max, 100% in this case, easily visible on the FW190). You just set it and go, but remember to be kind to your engine, set engine RPMs ('prop pitch' in FB) lower in non-combat situations to conserve fuel and run cooler.

Variable Pitch props, as in the BF109's are a different story, but I won't get into that (they do have an 'automatic' system to decrease pilot workload, which cause them to operate similar to a CSP).