Abstracts - EASY5 2000 User Conference

The following is a partial list of abstracts. Additional abstracts will be added when available.The following is a partial list of abstracts. Additional abstracts will be added when available.

Modeling for Advance Decision Making in Product Development

Dan W. Williams

John Deere

 This presentation is about the use of EASY5 as an analytical tool in support of product development at the John Deere Construction Equipment Company. It is intended to provide a glimpse of how simulation is being used to enhance development capabilities, improve product performance, and reduce the risk associated with new product introductions. A brief overview of the development culture will be included, followed by specific examples in which EASY5 has been successfully used on a new product line.

 

Integration of CAE Tools for Complete System Prototyping

Joel Tollefson

EASY5

This presentation describes the different methods of integrating Computer-Aided Engineering (CAE) tools. Examples of integrating tools are given, including co-simulation and coupled-simulation. This presentation will briefly describe how EASY5 integrates with MATLAB/SIMULINK®, and the MATRIXx® product family; multi-body tools including DADS®, ADAMS® and Pro/MECHANICA®; structural analysis tools like NASTRAN® and ANSYS®; CATIA®; and automatic code generator tools GSDS and BEACON®.

 

EASY5 and Integrating Boeing's Systems Design Environment

Bruce Fritchman

Dynamics Systems Analysis, Boeing

Aerospace products require the integration of complex systems: structural, mechanical, electrical, hydraulic, environmental, software and computing systems are among some of the systems that make up a modern airliner, missile, rocket engine or satellite. Boeing is striving to streamline and consolidate its systems design processes; from preliminary design studies through product verifi-cation and testing. Concurrently Boeing is engaging its subcontractors and systems suppliers to perform more and more of these systems engineering and integration functions at the same time it is moving towards single-source product data definitions of its products. This talk will focus on the role EASY5 plays in building this integrated systems design environment at Boeing.

 

Role of EASY5 in Advanced Process Integration for Rocket Engine Development

Frank Gombos

Rocketydne Propulsion Division

 This presentation will focus on the role of EASY5 in the development, optimization, and system verification of rocket engines at Rocketdyne Propulsion Division (RPP). Describes a process adapted by RPP to integrate product design and system development tools by inter-linking EASY5 models, and linking CAD/CASE tools in order to reduce design cycle time and cost. Applications cover preliminary system design, design optimization, control system development, and system verification.

 

Auto-Generation of EASY5 Models Using XML Data

Brian Ummel

EASY5

 A research and development program is developing an XML-based tool which allows CAD data to automatically generate EASY5 models of systems (hydraulic, fuel, ecs, thermal management, propulsion, electric power, and others). This tool uses XML (Extended Markup Language) specification to define an interface between EASY5 and other CAD software tools. The presentation focuses on what XML is, the XML-EASY5 specification, and live examples of taking an XML-EASY5 data file and automatically generating an EASY5 model.

 

Auto-Generating Functional Dynamic Models from CAD Data

Raju Mattikalli

Boeing

 Boeing has been developing the Genesis generative design system that uses engineering domain knowledge to reason about designs and to generate new parts and assemblies. The Knowledge-Based Integrated Routing Tool for Systems (KIRTS) contains design knowledge about aircraft systems to interactively generate tubing assemblies, built on Genesis. This system is being used today for designing systems tubing for the new 767-400 and 747-400 IGW (Increased Gross Weight) aircraft.

 

Integration of EASY5/GSDS for Auto Code Generation and Testing

Mike Bingle

Boeing

 Auto-code generation for the largest development real-time simulation in the world: the all-digi- tally-developed and tested Boeing 777. The Graphical Simulation Development System (GSDS) is a Boeing-developed toolset used for the design, documentation, and automated coding of air- craft systems, subsystems and LRU (Line Replaceable Units) within the Boeing Commercial Air- plane Systems Laboratory. Its primary features include a graphical diagram editor, a multi-user database facility, and automatic source-code generation. Diagrams may be analyzed and verified within the graphical editor for completeness, syntax, type checking, implicit and validity of feed- back loops, and initialization and parameter connection requirements. The code generation utility supports Fortran, C, Ada and Pascal and features an assortment of options for code configuration control. Documentation generation features allow for diagram and dictionary information to be automatically generated in special formats for publication purposes. New capabilities support user-transparent and controllable fixed-point types and arithmetic.

 

Modeling & Simulation of Aircraft Cargo Mechanical Systems

Brian Lojko

Lockheed Martin Aeronautic Systems - Marietta

The C-5 Aft Pressure Door is a very complicated system. Mechanically the door is designed to open from a lower hinge line and act as a loading ramp for aircraft, boats, and tracked and wheeled vehicles. The door is also capable of opening from an upper hinge for the purpose of conducting aerial delivery in support of airborne missions. The door is powered by an equally complex hydraulic circuit.

Lockheed Martin Aeronautics Company - Marietta was placed under contract by the U.S. Air Force in order to improve the fatigue life of certain structural components. EASY5 and DADS/Plant were used to create a virtual prototype of the door for the purpose of testing modifications to the hydraulic circuit in support of this contract. A physical test was conducted that validated the simulation results.

 

EASY5/ROCETS Dynamic Fluid Simulation Package

Randy Follet

Mississippi State University

 Computational models for dynamic fluid flow simulation are needed to predict the pressures, temperatures, flowrates, etc. for various cryogenic fluids in present and future testing operations at various test facilities such as the ground test facilities at Stennis Space Center (SSC). Such simulations are used in facility design, test scenario development, facility modification, and facility control. The Rocket Engine Transient Simulation (ROCETS) package, which was initially developed by Pratt and Whitney for NASA Marshall Space Flight Center, and EASY5x are the two major components which comprise the EASY/ROCETS dynamic fluid flow simulation package, which has been developed by Mississippi State University personnel for use at NASA/SSC. Additional code has been written to handle tasks specific to ground test facility modeling such as pressured gas bottle discharge and transient heat exchange. This paper presents the current status of this package, both in terms of technical development and commercial availability.

 

Modeling & Simulation of Agricultural Tractor Control System and Hydraulics

Dick Kading

LMS CADSI

 This example shows how DADS and Easy5 can be used to create very high fidelity simulation models. This application shows the modeling and simulation of a tractor's complex hydraulic system.

 

Getting the Most out of EASY5 Version 6.0
Peter Kamber
EASY5
 This presentation gives an overview of the new features in EASY5 version 6.0. Demos will given and the emphasize is on using the new features to improve your usage of EASY5.

 

 Modeling Electrical Power Systems using EASY5

Paul Mezs

EASY5

Farhad Nozari

Boeing

 

EASY5 has been successfully used to model systems involving thermal, mechanical and hydraulic components. However, EASY5's versatility can be extended to modeling of electrical systems. In this presentation, various examples of electrical system modeling using EASY5 are provided. The examples include induction motor drives, systems involving both electrical and mechanical components, and entire electrical power systems. Results of system level studies show the level of detail that can be attained using EASY5.

The basic theory of electrical machine modeling is introduced. Additionally, it is shown that power electronic devices can be built using EASY5. The waveforms of a pulse-width-modulated power supply model are provided. It is demonstrated that simulations involving detailed waveform switching will take longer than those using the fundamental component of the power supply output. The fundamental mode representation will in most cases produce comparable results in much less time.

 

Presentation of a Fuel-Air Tank System Library Made for Air-Pressurized Fuel Systems in Aircrafts

Hans Ellstroem

SAAB Linkoeping, Sweden

The application of SAAB's Fuel-Air System Library to the JAS39 Gripen Fuel System, with the control-box incorporated, will be shown. SAAB's original code of fuel-air tank system was old Fortran code. The code was not very user-friendly, the modeling input was cumbersome with a lot of data input making it easily to make errors. The conversion and update of the code into EASY5 presents a good example of how old code and knowledge can be transferred to new generations and survive in the mouse and window era. The conversion was very straight-forward and easy. It is obvious that EASY5 is meant for the users to implement their own components.

The fuel system modeling code main features include:
* Fully bidirectional network concept, i.e. resistive pipes, etc. are connected between tanks or nodes.
* Switching between fuel and air is handled automatically, depending on the fuel level in the tanks.
* Varying g-load vector in a 2D-layout is handled.
* Emphasis on simple and fast rather than extremely accurate.
* SI-units.
* Complete, self-contained library.

 

Using EASY5 to Teach Multidisciplinary Analysis Methods

Mel Human

North Carolina A&T State University

 An acute goal of upper undergraduate and graduate instruction is weaning students to think "inter-multidisciplinary," which is contrary to the course by course structure of college education. This talk reflects the author's experience in using Easy5 as a computational tool which addresses interdisciplinary coupling in a visually digestible format. Among several technical problems reflecting industrial practice, the primary example is showing the coupling of structural response, propulsion perfromance and control techniques in the design of a hypersonic aircraft construct. While mechanical response tends to be relatively accepted by engineering students as they can "see it," control theory concepts such as moving poles and zeroes, and frequency plots tend to be obscure in not only content but application. This talk tells of the author's success in showing students the direct physical relationship between such entiites and more tractable items such as wing movement and fuel throttling. Easy5 components from thermal hydraulics and actuator design libraries are used in these models.

 

 Pneumatic Systems Modeling with EASY5’s Gas Dynamics Library

Dan Thomas

EASY5

The capabilities of the new EASY5 Gas Dynamics (GD) Library will be presented. This library will be capable of modeling pneumatic control and actuator systems as well as gas transmission, chemically reacting gas systems and environmental control systems. Component groups include valves, orifices, pipes, nodes and volumes, actuators, actuator kit and valve kit primitives, heat exchangers and gas-cycle machines. In addition to the ideal gas equation of state, a built-in real gas equation of state will be available, or users will be able to supply their own gas property routines. A model of a pneumatic linear-position control system will demonstrate some of the capabilities of the GD library.

 

Modeling Air Conditioning System Noise in Aircraft using EASY5’s ECS Library

Gene W. Stubbs

BCAG Noise Technology

 Air conditioning system (ECS) noise is a significant contributor to aircraft interior noise. To aid airplane program noise staff engineers in assessing the cabin impact of ECS noise, we have developed an Easy5 library of duct components containing noise algorithms. The library is based on the Easy5 'ec' library of flow modeling components and others. In-duct, octave band flow-generated noise and attenuation are calculated using HVAC formulas and curve fits to test data. Acoustic reflections at duct terminations and junctions are modeled as continuous states. Noise radiation from outlets and duct breakout are used as inputs to airplane cabin noise models.

 

Model of Series Redundant Pressure Regulator of Bi-propellant Propulsion System Using EASY5's Gas Dynamics Library

Jasen Cheung

Stanford Mu Corp.

This presentation discusses the modeling of a series redundant pneumatic (GHe) pressure regulator of the bi-propellant propulsion system in the A2100 propulsion platform using the EASY5 Gas Dynamic Library. Highlights of modeling of some critical flow and moving mass spring mechanisms are included. Satisfactory simulation results were achieved in predicting dynamic and steady state performances of the pressure regulator due to excessive obstruction of its flow restrictor sensors. Some test results were also made available for comparison.

 

A Thermal Hydraulic Model for Expendable Launch Vehicles

Mike Berglund

Boeing

There exists a need for an analytical model than can describe the behavior of hydraulic systems on expendable launch vehicles under transient conditions. Current models used at Boeing Huntington Beach only describe steady-state conditions. Because of this, empirical data must be gathered to understand what happens to the hydraulic system under non-steady-state conditions. Gathering data in this way is expensive and time consuming. Modeling the system using EASY5 can reduce the number of expensive hardware tests.

This presentation describes an EASY5 model of the entire hydraulic system for the Delta IV Launch Vehicle. The model simulates transient conditions and compares extremely well with the test data. The presentation discusses these results and illustrates how EASY5 can be applied to hydraulic systems for space applications.

The presentation also provides tips and a summary of the process of creating a hydraulic model on EASY5. For these reasons, this presentation is valuable for the 1999 EASY5 User Conference for all those interested in modeling hydraulic systems.

 

Improved Simulation of Hydraulic System Pressure Transients using EASY5

Arun Trikha

The Boeing Company

The EASY5 components available in its Hydraulic Library go a long way in providing the building blocks required for simulating pressure transients in the hydraulic systems. However, there are some inherent limitations in trying to simulate wave travel effects in hydraulic lines with lumped line models used in EASY5 components PW and PX.

This paper discusses a new method of simulating a hydraulic line using EASY5. This method provides better pressure transients results through combining simulation of wave effects by time delays with an accurate simulation of the frequency-dependent friction effects. Comparison is made with similar results using PW component for hydraulic lines to demonstrate that the results using the new model are more accurate, don't display spurious oscillations in response, and are computationally faster. Further, the results from the new line model match those achieved by solving the partial differential equations for the line dynamics (for a simple system) in a closed form.

At this time, each of the hydraulic line was modeled as a submodel with calls to 2 CD (Continuous Time Delay) components, 5 LA (First Order Lag) components and 2 FORTRAN blocks. This submodel is currently being packaged into a new EASY5 component for easier set up of a hydraulic system model by a user.

 

[return to top]


revised: May 4, 2000