Turbulence and turbulent flow structures in a ventricular assist device-A numerical study using the large-eddy...

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Cardiovascular Devices

Background:

• Turbulent flow in ventricular assist devices (VADs) can damage blood components, increasing hemocompatibility risks.
• Optimizing VADs requires understanding turbulent flow and its impact on blood damage prediction.
• Detailed analysis of turbulence and local structures causing high shear stress in VADs is lacking.

Purpose of the Study:

• To comprehensively investigate turbulence in an axial VAD.
• To identify specific flow regions and structures responsible for high turbulent stresses.
• To establish the universality of these turbulent regions in axial blood pumps.

Main Methods:

• Utilized large-eddy simulation (LES) to compute flow in an axial VAD, resolving most turbulence.
• Employed a novel power loss analysis method for global quantification of turbulent flow state.
• Identified local flow regions and structures with significant turbulent stresses.

Main Results:

• Large-eddy simulation effectively resolved turbulence in the axial VAD.
• Power loss analysis provided a global measure of the turbulent flow state.
• Specific universal flow regions and structures associated with high turbulent stresses were identified.

Conclusions:

• The study successfully characterized turbulence in an axial VAD.
• Identified turbulent regions are likely universal across similar axial blood pump designs, including HeartMate II.
• Findings provide a basis for VAD design optimization to minimize blood damage and improve hemocompatibility.