Post on 22-Jan-2022
CFD AnalysisCFD Analysis
� 20 mm inlet diameter (19 mm for E85) creates choked flow conditions,
limiting total mass airflow to engine
� Required by competition rules
� Keeps engine power at a safe level for competition
Intake Restrictor
� Design goal is to minimize loss coefficient through restrictor geometry to
allow maximum airflow into engine
� Supersonic Converging – Diverging Nozzle Geometry
� Expand out diverging section to allow for proper shock development to minimize loss
coefficient
� Keep diffuser angle low enough to avoid potential flow separation
� Keep overall length low to reduce viscous losses due to surface friction and boundary
layer growth
� 2-Dimensional Axis-Symmetric analysis allows for fast solving time with refined mesh in
areas of shock development
Intake Restrictor
� Air flows from throttle to engine intake port through intake manifold
� Intake Plenum
� Acts as air reservoir for engine to draw air from during intake stroke
� Primary purpose is to damp out pressure pulses from intake stroke to create steady flow
Intake Manifold
� Primary purpose is to damp out pressure pulses from intake stroke to create steady flow
conditions at the restrictor
� Intake Runner
� Path through which engine pulls air from the plenum into the combustion chamber
during intake stroke
� Length decided by harmonic frequency at various engine operating speeds, can be used
to create a resonant “tuning point”
� Transient Pressure Boundary Condition used to simulate pressure pulses
within manifold from intake stroke
� Piecewise-Linear Approximation used for initial analysis trouble-shooting
� End analysis will use pressure trace measured during Dynamometer Testing
Intake Manifold
� Component Simulation
� Shroud structure analyzed to ensure uniform airflow distribution across radiator face and
verify proper mass airflow through radiator
� Radiator modeled as a material resistance with heat addition and flow re-direction to
properly simulate airflow through core
Cooling System Airflow
properly simulate airflow through core
� Full Car Simulation to verify shroud is receiving adequate airflow
� Simulation model still in progress, needs additional geometry and refinement
Cooling System Airflow