The Virtual Manikin Project

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The Virtual Manikin Project

• Andy Buxton
• Adrian Huggins
• David Glynn

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The Defence Evaluation Research Agency

• This work was carried out as part of Technology
  Group 5 (Human Sciences and Synthetic
  Environments) of the MoD Corporate Research
  Programme

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DERAs Ultimate Customers the Front Line
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Fundamentals of heat stress
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Experiment or Model?

• Experimental methods
• Laboratory or field based
• Expensive
• Specific
• Possibly hazardous

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Instrumented manikins for clothing evaluation

• Thermal manikin
• Thermal resistance (insulation)
• Sweating manikin
• Evaporative resistance

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Virtual Manikin Project Objectives

• Create a tool for modelling and assessing
  potentially hazardous environments
• Create a tool for assessing clothing systems
  prior to construction
• Reduce costs and time-scales for equipment
  procurement

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Geometry - STL file produced by laser scanning
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Cartesian grid details

• Grid dimension
• 38x52x56
• Domain dimension
• 2.5 x 2.0 x 1.9 m

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Boundary Conditions Source Terms

• Open pressure boundary conditions at front, sides
  and top of domain
• Inlet boundary condition specified at front for
  forced convection case
• Initial and inlet temperatures 20oC
• Bouyancy forces represented using Boussinesq
  model
• k-e turbulence model used
• Manikin heat source CO1.E5,VAL34oC

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Air movement and temperature contours
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Predicted manikin heat loss
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Human thermo-physiological model
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Information exchange

• Virtual Manikin-CFD model calculates local
  boundary conditions for physiological model
• Physiological model dictates heat and mass
  (sweat) sources for the CFD model

Virtual Manikin - CFD model
Thermo-physiological model
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Information flow
Initial conditions
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Current PARSOL treatment
FLUID

• PARSOL currently treats fluid flow differently
  from heat transfer (see figures)
• Fluid - Solid interfaces are treated correctly as
  a spline for fluid flow and as a staircase
  for heat transfer
• There can only be one fluid- solid interface in a
  given mesh cell

SOLID
FLUID
SOLID
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Extended PARSOL treatment
Fluid
Fluid
Solid
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Clothing simulation

• The clothing model will require integration of a
  number of features in PHOENICS
• Moving objects
• Stress-Strain
• Fluid flow
• Heat transfer
• Pre-existing algorithms will be used for the
  deformation of clothing

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Summary - 1

• An STL file of a manikin was produced by laser
  scanning
• This was imported into PHOENICS
• Flow simulations were produced and heat transfer
  predictions made
• Further grid refinement is required
• A parallel cluster of PCs will be used for future
  work

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Summary - 2

• The CFD model will be linked to a human
  thermo-physiological model
• More complex environments will be evaluated, e.g.
  vehicles, aircraft
• PARSOL will be enhanced-
• Unify current treatment of Fluid Flow and Heat
  Transfer
• Extend PARSOL to allow multiple interfaces in any
  given cell
• The extended PARSOL feature will be available to
  all PHOENICS users

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Points of contact

• Andy Buxton, David Glynn,
• Protection and Performance Department,
  Flowsolve Ltd.
• Centre for Human Sciences, Arthur Road,
• DERA, Ively Road, Wimbledon Park,
• HANTS. GU14 OLX. Tel. [phone]
• United Kingdom Fax. [phone]
• Tel. [phone] cfd_at_flowsolve.com
• Fax [phone]
• email acbuxton_at_dera.gov.uk