Jump to content

Archived

This topic is now archived and is closed to further replies.

arizona84

FSX - where to show fuel burn in defalut DHC2 Beaver?

Recommended Posts

I think there isn't one.. just time it for a half hour or something, then you know.

Or google it..

first link http://www.avcanada....hp?f=25&t=80470

 

20gph.

 

There isn't one is the answer i want . B)

the link you gave me , i can't understand fully coz I m a Chinese.

 

take a example:

 

Every CPL should know this rule of thumb:

 

To estimate your fuel burn at WOT at takeoff, drop a zero off your horsepower.

 

Seriously. 200hp, 20 gph at WOT. 300hp, 30 gph at WOT.

 

You probably cruise at 65% power. Without leaning very well,

take 2/3 of the above WOT fuel burn.

 

For example, 300hp takeoff burn is 30 gph, cruise 20 gph.

 

Obviously if you pull the throttle (and the mixture) back, you can

do better. But the above rule of thumb gets you in the ballpark.

 

See BSFC if you care to learn more

 

the red I have no idea what's it.

any basic handbook for a fresh so i can study from?

 

Thanks again!

Share this post


Link to post
Share on other sites

Ideal Flight 10 utility will show your fuel consumption rate as you fly. I think the demo shows this feature but not sure as I have the full version.

Share this post


Link to post
Share on other sites

the red I have no idea what's it.

 

That's ok, I don't know what CPL, WOT or BSFC is either.

 

"drop a zero off" means to remove the last zero. For example, if you have 450 horsepower, dropping the zero off means you have 45 gallons per hour at take off power.

 

Edit to add: It's the same as dividing by 10.

 

"in the ballpark" means "close". The term comes from baseball.

 

Hook

Share this post


Link to post
Share on other sites

thanks you guys. I understood after explaination.

As Lhookins told, 450HP engine consumpt 45gal. per hour when take off, that must mean at full power settings.

What if during cruise?

 

Because I saw a formule in FSP forum to calculat the fuel burn during the whole flight,

but two important datas are needed:

1.Fuel Flow/Hour 2.Ground speed(KTAS). BOTH IN CRUISE.

That's why I want to know FF/hour.

 

 

Ask one more. How to setup the Throttle/Prop/Mix etc.

Any basic knowledge I can check those data?

It's hard to google this kinda book with Chinese version, but English one maybe hard for me to understand.

Share this post


Link to post
Share on other sites

450HP engine consumpt 45gal. per hour when take off, that must mean at full power settings.

What if during cruise?

 

At cruise it will be 2/3 of that, or 30 gallons per hour.

 

Actually, the usual fuel consumption for the Beaver should be 20 gallons per hour, so figure 30 for takeoff.

 

Your ground speed will not be the same as true airspeed (KTAS) because of wind. If you're flying into a headwind, subtract the wind speed from the KTAS to get ground speed. If flying with a tailwind, add wind speed to KTAS. If the wind is from an angle, estimate it. For example, if the wind is from 45 degrees then you will add or subtract 70% of the wind speed.

 

If your KTAS is 120 and you have a 20 knot headwind blowing from 45 degrees off your front, your ground speed will be 120 minus 0.7 times 20 and that gives a ground speed of 106 knots. If you're flying 200 miles, it will take 200 divided by 106 hours, or 1.89 hours, times 20 gallons per hour for 37.8 gallons. Add a 15 gallon reserve so you can fly another 45 minutes if you can't land at your destination. I'd take off with about 55 gallons.

 

Hook

Share this post


Link to post
Share on other sites

Ask one more. How to setup the Throttle/Prop/Mix etc.

Any basic knowledge I can check those data?

Actual numbers will depend upon engine specifications. However, think of a variable speed prop as setting the engine RPM (each engine will have an optimal RPM for each condition). Think of the throttle setting the manifold pressure to an optimal setting. Think of the mixture control adjusting the air to fuel ratio...it is at its optimum when the mixture is leaned to the point when the cylinder head temperature begins to rise. An old technique used by early day pilots was to set the magneto switch to left or right, then lean the mixture until the engine begins to miss, then switch again to both magnetos.

Share this post


Link to post
Share on other sites

1.Think of the throttle setting the manifold pressure to an optimal setting.

2.Think of the mixture control adjusting the air to fuel ratio...

3.An old technique used by early day pilots was to set the magneto switch to left or right, then lean the mixture until the engine begins to miss, then switch again to both magnetos.

 

1. got it

2. got it

3. not get you.

That's also a question to me, what does left & right mean on the magneto switch?

For a single Engine, what's mean LEFT or RIGHT?

 

Back to my thing, for mixture is ok coz FSX will take care of it.

And how can I know if the settings i'm using is best for performance under a certain condition?

Any rules or experience(like '3 to 1 rule') to adjust them?

 

Many thanks!

Share this post


Link to post
Share on other sites

That's also a question to me, what does left & right mean on the magneto switch?

For a single Engine, what's mean LEFT or RIGHT?

 

Back to my thing, for mixture is ok coz FSX will take care of it.

And how can I know if the settings i'm using is best for performance under a certain condition?

Any rules or experience(like '3 to 1 rule') to adjust them?

 

Piston aircraft engines have two magnetos. One is designated "left" and the other "right". They could as easily be labeled "1" and "2". You check each one separately on pre-flight check and then you check both together.

 

Upon takeoff and landing, you'd normally set mixture to full rich. Upon cruise, if your panel has a cylinder head temperature gauge you set your mixture to lean gradually until the temperature begins to rise. Then back off a little, Every barometric pressure change (altitude) will require a new setting. If your panel doesn't have a gauge, you can only guess. I think FSX will take care of it for you. Happy flying!

Share this post


Link to post
Share on other sites

Upon cruise, if your panel has a cylinder head temperature gauge you set your mixture to lean gradually until the temperature begins to rise.

 

If mixture has any effect at all on cylinder head temperature, I have been unable to find it.

 

CHT is only affected by prop RPM (which causes it to rise) and airspeed (combined with outside air temperature and cowl flap settings, which causes it to fall).

 

The usual way to determine cruise mixture is to lean the mixture until the engine starts to run rough (or in the case of FSX when you start to lose power rapidly), then enrich it back to that point and add a bit. If you have an exhaust gas temperature gauge, which the Grumman Goose does, lean the mixture until the EGT is at max. A real world aircraft is a bit more complicated, but this procedure works well in FSX, and the EGT is somewhat simplified. There is a maximum EGT that you don't want to go over, but I don't think you can reach the real world value in the Goose without an air file tweak.

 

During takeoff, enrich the mixture to get the maximum fuel flow. During cruise, lean the mixture to get maximum exhaust gas temperature. Some people prefer to run slightly rich of maximum EGT, but it's up to you.

 

Hook

Share this post


Link to post
Share on other sites

Upon takeoff and landing, you'd normally set mixture to full rich. Upon cruise, if your panel has a cylinder head temperature gauge you set your mixture to lean gradually until the temperature begins to rise. Then back off a little, Every barometric pressure change (altitude) will require a new setting. If your panel doesn't have a gauge, you can only guess. I think FSX will take care of it for you. Happy flying!

 

I will try when i back home. thanks!!

Share this post


Link to post
Share on other sites
Guest BeaverDriver

Figure on 20 gph per hour cruise, leaned out. Add 5 to 10 gallons for each takeoff and that'll will get you close enough. Maybe up it to 25 gph in winter, but I'm not sure FSX models the difference (I'm using real world numbers from when I flew them in the bush).

 

@Hook - no cowl flaps on a Beaver. Power settings (including how lean you run the engine) and air flow through the cowl determine CHT. I've had the readings in the yellow during a hot and heavy climb to 2500 agl and close to full rich mixture and at the bottom of the green on a cool, damp day fully leaned out in cruise. Temps vary a lot in a Beaver with environmental conditions.

 

Hope that helps.

Share this post


Link to post
Share on other sites

no cowl flaps on a Beaver.

 

None on the Goose, either. Next time your CHT rises, try pulling the RPM back a bit.

 

I haven't seen any indication that the mixture and EGT has any effect on CHT in cruise.

 

Hook

Share this post


Link to post
Share on other sites

CHT raising too slow to notice, even I set the mix to lean about 20% while the engine can hardly 'breathe'.

i need more and more test i guess.

Share this post


Link to post
Share on other sites
Guest BeaverDriver

Well, it's probably not modeled in the sim aircraft, so that may not have any effect. IRL leaning has a major effect though. The leaner you run it, the hotter it gets, which will have an impact on the CHT. Ultimately airflow over the engine has the biggest effect (again, not sure if that will show up in FSX), so if you're climbing and it's getting uncomfortably hot (needle going into the yellow), it's time to lower the nose and go to cruise power for a while. As good as the default FSX Beaver is modeled (and it is VERY good), a couple of key things are not. One is the engine temp behaviour and the other is that IRL a Beaver won't climb unless you have flaps set to CLIMB. You can pull the nose back a bit, but all it will do is simply slow down. Add flaps to CLIMB setting, and up you go. So there are some things that aren't in the sim for sure, but overall the feel of the default Beaver is the best I've seen outside of the real version.

Share this post


Link to post
Share on other sites

Well, it's probably not modeled in the sim aircraft, so that may not have any effect. IRL leaning has a major effect though. The leaner you run it, the hotter it gets, which will have an impact on the CHT. Ultimately airflow over the engine has the biggest effect (again, not sure if that will show up in FSX), so if you're climbing and it's getting uncomfortably hot (needle going into the yellow), it's time to lower the nose and go to cruise power for a while. As good as the default FSX Beaver is modeled (and it is VERY good), a couple of key things are not. One is the engine temp behaviour and the other is that IRL a Beaver won't climb unless you have flaps set to CLIMB. You can pull the nose back a bit, but all it will do is simply slow down. Add flaps to CLIMB setting, and up you go. So there are some things that aren't in the sim for sure, but overall the feel of the default Beaver is the best I've seen outside of the real version.

 

Thank u so much for detailed answer. B)

Share this post


Link to post
Share on other sites

Ultimately airflow over the engine has the biggest effect (again, not sure if that will show up in FSX), so if you're climbing and it's getting uncomfortably hot (needle going into the yellow), it's time to lower the nose and go to cruise power for a while.

 

First, thanks for the info on the real Beaver.

 

In FSX, CHT goes up with RPM increases, and goes down with higher airspeed and lower outside air temperatures. When climbing in the Goose, I've got it adjusted where at normal climb RPM and speed, at some point the CHT gets to high and you have to pull the RPM back a bit, 50 to 100 RPM at a time, to keep CHT from getting too far into the yellow. You could keep the same RPM and lower the nose to get some relief, but it's not as dramatic a change as lowering the RPM.

 

Hook

Share this post


Link to post
Share on other sites

×
×
  • Create New...