[Minoslas]

interesting update L-39 Albatros team, and the Advanced Turbofan Engine Model (ATEM).

http://forums.eagle.ru/showpost.php?...&postcount=398

Time for a new year's update on the L-39. Work has been continuing, even without status updates to this topic, so no need to worry about this project being on hold.

Hydraulic System Implemented
Main and Emergency Hydraulic Circuits
Main Hydraulic Pump Pressurization from engine bleed air
Interconnect Valving and logic
Hydraulic pressure consumers: Gear, Gear Doors, Flaps, Ram Air Turbine, Wheel brakes, Speed brakes (main system only)
Emergency Extension Levers for Gear, Flaps, and Ram Air Turbine
Emergency Brake Lever

Miscellaneous
Random failures code was started, but has been put on hold for now
Fixed several major bugs (for ex: Engine would shut off during air starts)

Advanced Flight Model
Tweaks to Yaw Stability and Rudder Effectiveness

Advanced Turbofan Engine Model
I began work on this new fully dynamic engine model back in October, but it has not been implemented into the simulator at this point, so many things are still subject to change. However, I thought I would pass along some details about the planned features of this new turbofan engine model for the L-39. So far, I have written the entire engine model into a standalone program that runs at the same frequency as the DCS flight model and reads my throttle inputs in real time to simulate realistic dynamic conditions. I also view the output of the engine conditions in real time in several performance graphs.
Improved Thermodynamic Model that accounts for enthalpy changes across each subsection of the engine given inefficiencies and current dynamic conditions
Inertial Twin Spool Rotor Modeling
Aerodynamic blade drag for each compressor/turbine stage
Fuel Governor with a simple control algorithm to maintain sufficient fuel pressure at varying altitudes and airspeeds
Compressor/Turbine Efficiency Curves based on airflow and rotor speed
Two Anti-Surge Bleed Valves affect performance of the engine in the specified ranges for the L-39
Combustion efficiency dependent on Fuel/Air ratio
Air-starter Modeling of initial engine spool up
Light-off produces correct RPM acceleration and combustion allows for self-sustaining idle conditions
etc.

An example output from a slam acceleration/deceleration test in an early version of engine and fuel controller.