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Cannot properly increase propeller pitch and engine throttle  Topic is solved

Good sims require good FDMs (the "thing" that makes an aircraft behave like an aircraft).

Re: Cannot properly increase propeller pitch and engine thro

Postby S&J » Thu Nov 25, 2021 7:59 am

Yes VE table is being used
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Re: Cannot properly increase propeller pitch and engine thro

Postby TheEagle » Thu Nov 25, 2021 1:05 pm

Weird. What else could be different between our engines ?
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Re: Cannot properly increase propeller pitch and engine thro

Postby TheEagle » Thu Nov 25, 2021 4:45 pm

Well, this gets weirder and weirder. I was just testing my HSI, took a look at the horsepower values by the way, and got 285 on the runway and up to 340 on a descent at 230 kts. This was with the McCauley propeller, not with the PronyBrake - could that make a difference
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Re: Cannot properly increase propeller pitch and engine thro

Postby S&J » Thu Nov 25, 2021 6:46 pm

Yeh depends upon rpm
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Re: Cannot properly increase propeller pitch and engine thro

Postby TheEagle » Thu Nov 25, 2021 7:44 pm

On the runway I got 2700 RPM, on the descent almost 3000. Now what should I do ?
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Re: Cannot properly increase propeller pitch and engine thro

Postby S&J » Thu Nov 25, 2021 8:06 pm

Test the engine with a prony brake ?

Get it working correctly and then work on the prop
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Re: Cannot properly increase propeller pitch and engine thro

Postby S&J » Thu Nov 25, 2021 9:23 pm

And another thought... I have asked you about your mixture setting before but now is a good time to do a quick check.

set your plane at any alt above 6000ft and below critical alt.
It should be producing 310hp.

Then adjust your mixture, and if you can get more power out of your engine, your mixtures wrong.

Record the AFR value for when you have the max HP and then always use this value in your tests.
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Re: Cannot properly increase propeller pitch and engine thro

Postby TheEagle » Thu Nov 25, 2021 10:20 pm

S&J wrote in Thu Nov 25, 2021 8:06 pm:Test the engine with a prony brake ?

Okay - which HP value should I aim for - 310 (5 min limit) or 285 (max continuous) ?
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Re: Cannot properly increase propeller pitch and engine thro

Postby S&J » Thu Nov 25, 2021 10:33 pm

I thought 310 was it's 2700rpm, 35in map ?
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Re: Cannot properly increase propeller pitch and engine thro

Postby TheEagle » Thu Nov 25, 2021 11:14 pm

No.

5 minutes limitation: 2700 RPM, 310 HP, 36.5 inHg MP
Maximum continuous: 2600 RPM, 285 HP, 35.5 inHg MP
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Re: Cannot properly increase propeller pitch and engine thro

Postby TheEagle » Thu Nov 25, 2021 11:23 pm

You said the 5 minutes limit power we are going to simulate with some engine system functions - so should I target the 5 minutes limit or the maximum continuous with my tables ?
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Re: Cannot properly increase propeller pitch and engine thro

Postby S&J » Fri Nov 26, 2021 12:25 am

maximum continuous power.

which looks to be

2600 RPM, 285 HP, 35.5 inHg MP critical alt of 17,000ft

the intention is to use takeoffboost
https://jsbsim-team.github.io/jsbsim/cl ... iston.html

But for now we ignore it, cause it'll just cause throttle setting trouble and we'll add it later.

check your boost settings are as these

Code: Select all
<piston_engine name="Continental_TSIO-520-P">

   <displacement unit="IN3">520.00</displacement>
   <bore unit="IN">5.25</bore>
   <stroke unit="IN">4.0</stroke>
   <cylinders>6.0</cylinders>
   <compression-ratio>7.5</compression-ratio>
   <maxhp>285.00</maxhp>
   <cycles>4.0</cycles>
   <idlerpm>600.0</idlerpm>   
   <maxrpm>2600.0</maxrpm>   
   <starter-torque>50.00</starter-torque>   
   <static-friction>1.55</static-friction>
   
   <ram-air-factor>0.81</ram-air-factor>
   <air-intake-impedance-factor>0</air-intake-impedance-factor>

   <maxmp unit="INHG">28.8</maxmp>   
   <minmp unit="INHG">14.7</minmp>

      <boostmanual>1</boostmanual>
   <numboostspeeds>1</numboostspeeds>
   <boostoverride>0</boostoverride>
   <boost-loss-factor>0</boost-loss-factor>   
   <ratedboost1 unit="INHG">5.58</ratedboost1> <!-- 35.5inhg  -->
   <ratedrpm1>2600</ratedrpm1>
   <ratedpower1>285</ratedpower1>   
   <ratedaltitude1>16000</ratedaltitude1> <!-- 17000  -->

   <sparkfaildrop>0.1</sparkfaildrop>
   <volumetric-efficiency>0.7938</volumetric-efficiency>
   <bsfc unit="LBS/HP*HR">0.4336</bsfc>

   <cylinder-head-mass unit="LBS">25.28</cylinder-head-mass>
   <cooling-factor>0.36</cooling-factor>

</piston_engine>
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Re: Cannot properly increase propeller pitch and engine thro

Postby S&J » Fri Nov 26, 2021 12:32 am

and the final piece of the jigsaw is fuel flow of 162lbs/hr
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Re: Cannot properly increase propeller pitch and engine thro

Postby TheEagle » Fri Nov 26, 2021 9:39 am

With boostmanual I had to set some property, right ? Or does it just set the boost speed, which doesn't matter because we have only one ?
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Re: Cannot properly increase propeller pitch and engine thro

Postby TheEagle » Fri Nov 26, 2021 10:04 am

I got 362 HP at 10000ft with AFR = 9.9
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