SDK 0.24.3 Engine.cfg - please add engine_mechanical_efficiency_table as mandatory and set proper defaults

Version: *SDK 0.24.3 - 1.37.19.0

Frequency: Consistently

Severity: *High

Context: building aircraft

Bug description: When a dev is starting out and is new they may rely on default values in the engines.cfg file. There are a number of mandatory parameters to set and they may start with default values. My research on how to provide some guidance to new devs would be to set only the mandatory values as shown in the SDK docs. However there are some default values that

a) don’t agree with the AE defaults in the FIleDefs_AircraftEditor.xml
b) should be added to the mandatory list

If you just use the piston engine defaults and prop defaults, and build the aircraft your aircraft will fly for about 10-20 seconds and you will see the fuel flow slowly drop until engine shutdown.

I have found that there should be two other parameters set by the dev:

engine_mechanical_efficiency_table
engine_friction_table

The SDK says that the default is 0:0 for both, but the FileDefs_aircrafteditor.xml has:

			<!-- INITIALIZED WITH DEFAULT VALUES ??? -->
			<!-- SIZE OF 6 BUT NO LABELS ? -->
			<Entry name="engine_mechanical_efficiency_table" type="2dArray" defaultValue="0:0.3, 1000:0.3, 2000:0.3, 3000:0.3, 4000:0.3, 6000:0.3" minSize='2' maxSize='8' required="false" label="Mechanical Efficiency">
				<SubEntry name="value1" type="float" required="true" label="RPM"/>
				<SubEntry name="value2" type="float" minValue='0' required="true" label="Efficiency Factor"/>
			</Entry>
			<!-- Unclear documentation -->
			<Entry name="engine_friction_table" type="2dArray" defaultValue="-1000:0.3, 0:0.3, 1000:0.3, 2000:0.3, 3000:0.3, 4000:0.3, 6000:0.3" minSize='2' maxSize='8' required="false" label="Friction">
				<SubEntry name="value1" type="float" required="true" label="RPM"/>
				<!-- <SubEntry name="value2" type="float" minValue='0' maxValue='1' required="false" label=""/> -->
				<SubEntry name="value2" type="float" required="true" label="Friction Torque"/>
			</Entry>

0.3 across the rpm spectrum. So which is the “proper default”?

Why not just use what you have in the simpleAircraft sample. you default to a 180 hp engine, so use these params

engine_mechanical_efficiency_table = 0:0.77, 700:0.77, 2000:0.67, 2200:0.54, 2700:0.54
engine_friction_table = -300:-25, 300:25, 500:25, 2700:31

EDIT:
egt_peak_temperature is default zero but template is 1660
egt_tc default 0 is 2 in template

Repro steps:

Attachments:

Private attachments: Send a PM to @PrivateContent with the link to this topic and the link to download your content

1 Like