Re: [Flightgear-devel] JSBSim Piston Engine Idle

2013-02-09 Thread Ron Jensen
On Saturday 08 December 2012 12:12:23 Ron Jensen wrote: I took a quick look through the FGData Aircraft directory today and came up with a list of some 27 JSBSim piston engines that still seem to be using either the old aeromatic default values for idle manifold pressure (minmp) or

Re: [Flightgear-devel] JSBSim Piston Engine Idle

2012-12-11 Thread Eric van den Berg
Ron, From experience: the lyco IO540 idles at 14-15 inHG, 900RPM (MT-prop with P-880-xx governor) Eric From: w...@jentronics.com To: flightgear-devel@lists.sourceforge.net Date: Sat, 8 Dec 2012 12:12:23 -0700 CC: jsbsim-de...@lists.sourceforge.net Subject: [Flightgear-devel] JSBSim

Re: [Flightgear-devel] JSBSim Piston Engine Idle

2012-12-11 Thread Ron Jensen
On Tuesday 11 December 2012 00:55:35 Eric van den Berg wrote: Ron, From experience: the lyco IO540 idles at 14-15 inHG, 900RPM (MT-prop with P-880-xx governor) Eric Thanks Eric, The JSBSim piston engine model is missing something, probably Mach effect through the intake valve, so models

Re: [Flightgear-devel] JSBSim Piston Engine Idle

2012-12-11 Thread Eric van den Berg
To: flightgear-devel@lists.sourceforge.net Date: Tue, 11 Dec 2012 06:20:23 -0700 Subject: Re: [Flightgear-devel] JSBSim Piston Engine Idle On Tuesday 11 December 2012 00:55:35 Eric van den Berg wrote: Ron, From experience: the lyco IO540 idles at 14-15 inHG, 900RPM (MT-prop with P-880-xx

Re: [Flightgear-devel] JSBSim Piston Engine Idle

2012-12-11 Thread Ron Jensen
On Tuesday 11 December 2012 09:46:10 Eric van den Berg wrote: I see. Looking at the code (I think) I can see you are trying calculate the pressure losses in the injector/throttle valve, airbox and inlet tubes. Using throttle position and engine speed (was expecting cylinder displacement here

Re: [Flightgear-devel] JSBSim Piston Engine Idle

2012-12-11 Thread Eric van den Berg
So it is kind of modelled like an air pump. Interesting method. BTW p0 =101325 Pa R = 287.05 Cp_air = 1004.68 gamma = 1.4 Handbook of Aviation fuel properties, third edition: net heat of combustion of AVGAS, all grades : min. 43.5 MJ/kg, 44 typical density of AVGAS: 710 at 15degC C_p_AVGAS =

Re: [Flightgear-devel] JSBSim Piston Engine Idle

2012-12-11 Thread Ron Jensen
On Tuesday 11 December 2012 13:49:51 Eric van den Berg wrote: So it is kind of modelled like an air pump. Interesting method. Piston engines are basically air pumps. We currently calculate power by dividing the mass fuel flow by the user-entered bsfc multiply by correction factors for mixture

Re: [Flightgear-devel] JSBSim Piston Engine Idle

2012-12-11 Thread Ron Jensen
On Tuesday 11 December 2012 13:49:51 Eric van den Berg wrote: So it is kind of modelled like an air pump. Interesting method. Piston engines are basically air pumps. We currently calculate power by dividing the mass fuel flow by the user-entered bsfc multiply by correction factors for mixture

Re: [Flightgear-devel] JSBSim Piston Engine Idle

2012-12-10 Thread Torsten Dreyer
I'd be grateful for an update of the Dragonfly and the ogeL. The Dragonfly's configuration was a wild guess, and only very vaguely based on real numbers. ogeL's engine is by definition just fantasy ;-) Thanks, Torsten Am 08.12.2012 20:12, schrieb Ron Jensen: I took a quick look through the