How To Model Internal Flows incEngineering Systems

How To Model Internal Flows in Engineering Systems

Webinar Presentation (PDF)
Webinar Recording (WebEx)
Note: The presentation file is only available to NAFEMS members.


Fluid sub-systems are a key part of many engineering systems from lubrication and fuel to hydraulics and pipelines. These systems are large, complex and often highly transient, and the flows are typically internal, pressurised flows – e.g. through pipes, valves and motors. They often require both passive and active control.

This talk will introduce 1D Fluid System Simulation (System CFD) and show how it is used to analyse and design internal flow systems in complex fluid engineering. We will compare system techniques with 2D and 3D CFD techniques – showing that they are complementary.

System CFD allows engineers to quickly build models based using catalogues of pre-defined components. System models are used to:

  • Perform sizing studies
  • Analyse system level transient flows including pressure waves, surge and cavity formation
  • See the big picture in complex engineering systems – e.g. analysis of bulk flow properties
  • System CFD supports the design lifecycle with simplified models early in design to explore concepts and more complex models being used later as the design crystallises - including integration of 3D CFD models
  • System CFD supports the use of model based design principles to facilitate synthetic design and the use of digital twin

The talk will present a number of case studies to discuss its use in analysis and design of engineering systems with surge; thermal management; hydraulics; rotating machine


  • Welcome & Introduction:
    • Mr. Andrew Wood, NAFEMS
  • Introduction to the CFD Working Group
    • Dr. Althea de Souza, Quesada Solutions, CFD Working Group Chair
  • How To Model Internal Flows in Engineering Systems
    • Dr. David Hunt, CFD Working Group Member.
  • Q&A and Discussion
  • Close

About the Speaker

Current position / tasks:

David HuntDr. David Hunt is a Senior Computational Physicist and manages Research, Design and Innovation at FloMASTER, a System CFD product in Mentor Graphics’ Mechanical Analysis Division (Siemens Company). 

David oversees Research and Design activities to enhance the simulation capability for gas turbine applications.
David works on developing capabilities to support Model Based Design and Synthetic Design and Design Optimisation. A key part of this work has been integrating 3D CFD with System CFD tools.

David has worked on novel algorithms to improve numerical stability within fluid simulations that allow robust simulation of components with complex physics and multiple armed components.


David has worked extensively in mathematical modeling across a range of industries from decision support systems in the rail industry through to attitude control systems in the space sector.

David worked for many years in the Research Group at the Aircraft Research Association on 3D CFD for external aerodynamics including:

  • Very Large Eddy Simulations on shock wave / turbulence interactions
  • Modeling external turbulent flows in aerospace and marine 
  • Drag prediction• Quasi-unsteady methodologies for store release and propeller simulations
  • Flow-Feature Extraction