what's next for electronics cooling...
TRANSCRIPT
What's Next for Electronics
Cooling Simulations?
Ruben Bons
CD-adapco
Outline
Historical electronics cooling CFD
Typical model characteristics in
electronics cooling simulations
Future of electronics cooling
simulations
– Geometric detail
– Physics fidelity
– Design exploration
Historical Electronics Cooling CFD
Typical Electronics Cooling CFD
Physically simple
– Simplified devices
• Fans & blowers
• Components
• Heat sinks
• Perforated plates
– Physics simulated
• Steady state
• Dry air
• Single fluid phase
Minimal variations
– Small matrix of design variants
– Small set of operating conditions
– Exact inputs
Geometrically simple
– Simple parts
• Flat faces
• Orthogonal faces
• No manufacturing features (e.g.
fillets, drafts)
– Simple assemblies
• All mechanical connectors
removed (bolts, screws, etc.)
• Small or “unimportant” parts
removed
What’s Next?
How will electronics cooling simulations
change in the next 5 – 10 years?
1. More detail: Broader length & time scales
2. More physics: Broader phenomena simulated in
more depth
3. More exploration: Design space sweeps, test
matrix, optimization, sensitivity
More Detail
More Detail
Main system
Sub-system 1
Sub-system 2
Sub-system 3
Sub-system 4
~100 m ~10 m ~1 m ~0.1 m ~10 mm ~1 mm ~0.1 mm ~10 µm ~1 µm
~10 s ~1 s ~0.1 s ~10 ms ~1 ms ~0.1 ms ~10 µs ~1 µs ~0.1 µs
• Telecom chassis / boards
• Data center / racks
• Server room / server blades
More Detail
1 2 3 4 5 6 7
Front End Air Flow• Top Tank Temperature
Prediction1
Local Component Temperature• 30-60 Solids• Local to a component
2
Total Vehicle Simulation• Using existing sub-models4
Underbody Temperature• ~ 100 Solids• Includes Exhaust System, hangers,
engine mounts, heat shields
3Power Train Cooling• Full Engine CHT model• Induction System• Exhaust System• Oil Flow
5
Full Vehicle Thermal Management• Conduction/Radiation• Includes Drive Cycle Simulation
6
Full Vehicle Thermal Management• Co-Simulation from STAR-
CCM+ to STAR-CCM+• 4000 Solid Components• Includes Drive Cycle
Simulation via Ports
7
8
GUM: Grand Unified Model• Complete vehicle simulation
• 4000+ Solid Components• Cabin Thermal Comfort• Vehicle Aerodynamics• HVAC Simulation• Electronics Cooling
• Co-Simulation STAR-CCM+ to STAR-CCM+
8
More Detail
More Detail: Why? When?
• If flow rate is the
same the thermal
resistance is
accurate.
• With fan-driven
flow, the error in
pressure drop
causes large error
in flow rate &
thermal
resistance.
Simplified to…Accurate?
More Physics
More Physics
ngspice
More Physics
More Physics: Why? When?
Fan Model
No CAD needed Fewer cells Short runtime Less accurate
Steady (MRF)
CAD needed More cells Moderate runtime More accurate
Unsteady
CAD needed More cells Long runtime Most accurate
Fan Curve
dP
Q
Fan Simulation Options
More Physics: Why? When?
Fan Curve Steady Unsteady
Maximum 37.5 C 39.7 C 39.9 C
Error 12.7% 1.1% --
More Exploration
More Exploration
Geometry
MaterialsMesh Conditions
Solution
Results
Design exploration /
Optimization
More Exploration
Design of Experiments
– Define range of inputs
– Compute response surface
Stochastic Analysis
– Statistical distribution of inputs
– Compute distribution of results
Design Exploration
– Define matrix of designs / tests
– Automatically test design points
Optimization
– Set goal & allowable changes
– Heat sink optimization in the context of the entire system
– Include fan & vent placement
Inputs
Outputs
What’s Next?
How will simulation for the electronics industry
change in the next 5 – 10 years?
1. More detail: Broader length & time scales
2. More physics: Broader phenomena simulated in
more depth
3. More exploration: Design space sweeps, test
matrix, optimization, sensitivity
