A Hydrodynamic Model for Measuring Fluid Density and Viscosity by Using Quartz Tuning Forks

Area of Science:

• Physics
• Materials Science
• Chemical Engineering

Background:

• Quartz tuning forks (QTFs) are utilized for sensing applications.
• Atomic Force Microscopy (AFM) principles can be adapted for fluid property measurements.
• Accurate real-time fluid analysis is crucial in various industrial applications.

Purpose of the Study:

• To establish a hydrodynamic model for density and viscosity sensing using QTFs.
• To quantitatively analyze the influence of fluid properties on QTF parameters.
• To improve the accuracy of fluid component recognition and sensor design.

Main Methods:

• Developed a hydrodynamic model based on cantilever beam theory for QTFs.
• Applied the Sobol index method to determine parameter sensitivities.
• Validated the model with experimental data for eight different solutions.
• Compared model performance against the Butterworth-Van Dyke equivalent circuit method.

Main Results:

• The hydrodynamic model demonstrated an order of magnitude reduction in relative mean square error for viscosity measurements.
• Increased sensitivity of the quality factor to fluid density was observed within specific QTF operating ranges (25,800–26,100 Hz, 28–41).
• The model accurately predicts fluid density and viscosity based on resonance frequency and quality factor.

Conclusions:

• The established hydrodynamic model offers improved accuracy for fluid density and viscosity sensing.
• This research lays the groundwork for developing miniaturized, cost-effective downhole sensors.
• The findings support enhanced real-time fluid component recognition capabilities.