Modelon Ab · OMXSTO:MODEL
Modelon Ab — Technical Presentation (July 2021)
35 slides from Modelon Ab's technical presentation, July 2021
Slide 1: Fuel System Library Overview
FUEL SYSTEM LIBRARY Overview
Slide 2: Agenda
AGENDA ❑ About Fuel System Library ❑ Key Benefits ❑ Key Capabilities ❑ Key Applications ❑ Library Contents ❑ Modelon Compatibility ❑ Latest Release: 2021.2 ©2021 Modelon 2
Slide 3: About Fuel System Library
ABOUT FUEL SYSTEM LIBRARY • Design and verification of fuel systems of civil and military aircrafts • Analysis and verification of system behavior during various dynamic operating modes and flight conditions, including effects of large variations in acceleration, direction and altitude • Provides si
Slide 4: About Fuel System Library
ABOUT FUEL SYSTEM LIBRARY Offline simulation of complete Fuel Systems through complete flight envelope and all operating conditions: • Large systems • Controls, sequential and feedback Real-time simulation of the same system models: • Some simplifications, but the same overall model (real time capab
Slide 5: Key Benefits
KEY BENEFITS ©2021 Modelon 5
Slide 6: Key Benefits
KEY BENEFITS • High performance and real-time capable • Import of 3D tank geometries from CAD • Physics-based models covering thermal, hydraulics, inerting, evaporation, solubility • Full support for bidirectional flow • Efficient property models of air-fuel mixtures • Easily switch off the thermal
Slide 7: Key Capabilities
KEY CAPABILITIES ©2021 Modelon 7
Slide 8: Key Capabilities: Medium properties
KEY CAPABILITIES Medium properties • Jet fuel • Jet-A, Jet-B, JP-4, JP-5, and JP-8 • Liquid medium with slight compressibility • Gas Mixture • Moist air (water with dry air or ideal dry air mixture) • No water condensation (𝜙 < 100%) • Evaporated jet fuel with dry air mixture • Mixture medium • All
Slide 9: Key Capabilities: Multiple Connector types
KEY CAPABILITIES Multiple Connector types Hollow connector Filled connector • pressure is a time • mass flow rate is continuous state computed from Dp • used in interface of p as state p not as state • used in flowmodel dynamic volumes set position set position interfaces • static eq: m_flow = f(Dp)
Slide 10: Key Capabilities: Position information
KEY CAPABILITIES Position information Pipes • Receive position information and cross sectional area from connected components • Receive acceleration vector via inner/outer • Optional dynamic momentum balance: pressure drop, static head and resistance losses can be computed from massflow as state All
Slide 11: Key Capabilities: Position information
KEY CAPABILITIES Position information flow area flow area + 3D-position + 3D-position fuel system valve=general fluid system valve + dynamic volumes (optional) + pipe length + positioning information + projection of acceleration vector on pipe length similar procedure for + fuel system connectors -
Slide 12: Key Capabilities: Fuel tank inerting
KEY CAPABILITIES Fuel tank inerting Purpose: • Fill air space in tanks with inert gas (N2) to reduce concentrations of oxygen and fuel to prevent combustion Medium properties use dry air mixture with variable composition of O2 and N2 ©2021 Modelon 12
Slide 13: Key Capabilities: Fuel evaporation
KEY CAPABILITIES Fuel evaporation Purpose: • Track amount of evaporated fuel in ullage Medium properties package for fuel evaporation • Evaporated jet fuel, O2, N2 and liquid jet fuel • Jet-A, JP-4, JP-5, and JP-8 Amount of evaporated fuel is based vapor pressure Jet fuel pseudo compound modeled in
Slide 14: Key Capabilities: Gas solubility
KEY CAPABILITIES Gas solubility • Tracking trace concentrations of oxygen and nitrogen dissolved in the liquid jet fuel • Assume dissolved gas does not alter thermodynamic properties of fuel or gas • Assume first order rate equation for dissolution and outgassing • Use data from the Aviation Fuel Ha
Slide 15: Key Capabilities: Aggregation of Fuel mass
KEY CAPABILITIES Aggregation of Fuel mass Automatically tracks total mass of fuel in large systems ©2021 Modelon 15
Slide 16: Key Applications
KEY APPLICATIONS ©2021 Modelon 16
Slide 17: Key Applications: Real-time
KEY APPLICATIONS Real-time Scope: • Develop complex and accurate models that can be run in real time • Use the same high-fidelity models throughout the design and validation process Relevant solution features: • Fuel Systems Library real-time mode • Inline integration • Mixed-mode integration ©2021
Slide 18: Key Applications: Inerting
KEY APPLICATIONS Inerting Scope: • Analyze the dynamic propagation of species like nitrogen and oxygen • Size the inerting system to ensure admissible oxygen concentrations throughout the envelope Relevant solution features: • Dynamic balance equations including full support of flow reversal • Set v
Slide 19: Key Applications: Fuel transfer/refueling
KEY APPLICATIONS Fuel transfer/refueling Scope: • Dynamically simulate fuel transfer and refueling of aircraft • Validate line, orifice, pump/ejector and balance tube performance • Simulate failure conditions including ejector induced and discharge flow reversal and pump cavitation Relevant solution
Slide 20: Key Applications: Flammability
KEY APPLICATIONS Flammability Scope: • Dynamically simulate mass and energy balance • Assess temperatures in relation to flash point/lower and upper flammability limits • Model heat transfer, mass transfer, solubility Relevant solution features: • Heat transfer to gas and liquid • Convective transpo
Slide 21: Example: Filling Tank
EXAMPLE: FILLING TANK Quasi-steady-state components: • Settings_FSL (1), AirData(1), Atmosphere(1) • Pipe (8) • Valve (1) • Sinks/sources (2) Mass and energy storage: • Tank (4) • Dynamic volumes (incl. e.g. moisture condensation) (2) ©2021 Modelon 21
Slide 22: Library Contents
LIBRARY CONTENTS ©2021 Modelon 22
Slide 23: Components
COMPONENTS Systems of Aircraft fluid • System settings like altitude, Mach number, etc Boundary conditions • Pressure source/sink • Mass flow source/sink • Options: set parameters, signal inputs, use atmosphere information from system component Pipe • Static head uses connection vector between ports
Slide 24: Components: Tank
COMPONENTS Tank y • Volume with one pressure and temperature state air + water vapor P1 • Distance of liquid level to port determines + fuel vapor port pressure – iteration variable or additional numerical state • Ports can be left unconnected a L1 ▪ input: P1, P2, a, V_liq L2 ▪ output: L1, L2 P2 V_
Slide 25: Components: Tank with Heat Transfer
COMPONENTS Tank with Heat Transfer • Volume with one pressure and temperature state • Heat port for each side of the box shaped tank • Calculate wetted surface area for each side • User-defined wet/dry heat transfer coefficient for each side ©2021 Modelon 25
Slide 26: Components: Complex Tank
COMPONENTS Complex Tank • Geometry defined by sets of vertices and triangles • Supports import of CAD geometries via STL files • Arbitrary number of heat transfer surfaces • Physical free convection heat transfer correlations distinguishing wet vs. dry surface, surface inclination etc. ©2021 Modelon
Slide 27: Components: Multi-Level Tank
COMPONENTS Multi-Level Tank • Simulate the behavior of a tank where basins are not communicating in certain configurations and thus can have different liquid levels in the same tank system • Tanks are modeled orifice models connected in-between • Geometry defined by sets of vertices and triangles •
Slide 28: Components: Sensors, Volume, Valves
COMPONENTS Ideal Sensors • Single port sensors: p, T • Two port flow sensors: m_flow, V_flow Volume • Dynamic energy and mass balances • Volume without hydraulic resistance Valves • Check valve • Control valve (Kv-value parameterization) ©2021 Modelon 28
Slide 29: Components: Pump and Ejector
COMPONENTS Pump • Hydraulic characteristics • Power characteristics • Cavitation influence by a reduction factor by parameterization Ejector • The motive flow is always positive, induced and discharge flow can change flow direction • Choked flow is not reached in the nozzle • Incompressible • Fricti
Slide 30: Modelon Compatibility
MODELON COMPATIBILITY ©2021 Modelon 30
Slide 31: Recommended Modelon Library Compatibility
RECOMMENDED MODELON LIBRARY COMPATIBILITY • Environmental Control Library • Moist air • Turbines • Fans • Compressors • Ejector • Aircraft Dynamics Library • Jet Propulsion Library • Liquid Cooling Library • Heat Exchanger Library • Hydraulics Library ©2021 Modelon 31
Slide 32: Example: Modelon Portfolio Multi-Domain System
EXAMPLE: MODELON PORTFOLIO MULTI-DOMAIN SYSTEM • Electric Power Library • Environmental Control Library • Fuel System Library • Heat Exchanger Library • Hydraulics Library • Liquid Cooling Library • Vapor Cycle Library ©2021 Modelon 32
Slide 33: Latest Release: 2021.2
LATEST RELEASE: 2021.2 ©2021 Modelon 33
Slide 34: Release 2021.2 New Feature
RELEASE: 2021.2 New Feature • A new complex geometry tank model supporting multi-level simulations is added. The flow through the tanks are modeled by an orifice approximating a rectangular weir as opening. • Devices to extract only liquid or gas from the multi- level tank are added. • Add ControlVa
Slide 35: Release 2021.2 Enhancements
RELEASE: 2021.2 Enhancements • Added a Boolean parameter visualize to the tank geometry kernels (ModelicaWithVisualization and ExplicitExternalWithVisualization) which supports 3D visualization. By default, it is set to true. Setting this to false will reduce result file size and simulation time con