気管支モデル内振動流のPIV計測

抄録

This paper aims to conduct PIV (Particle Image Velocimetry) measurement of oscillatory flow in the complex structure of human bronchus model. In this experiment, human respiration was simulated as a sinusoidal flow. The sinusoidal flow was generated by the plunger movement of syringe. The flow rate of the oscillatory flow was simulated as sinusoidal cycle. The oscillatory flow simulated resting human respiration (Re=1415, 20 breaths per minute). Human bronchus model was made of transparent silicon. A bent pipe was connected to the human bronchus model to simulate larynx. To match the refractive index of silicon model, glycerol aqueous solution (50% volume of glycerin) was used as working fluid. Microbubbles were used as tracer particle of the PIV measurement. YAG laser was used to illuminate the tracer particle. The PIV measurements were conducted in 3 areas which were around the bifurcation of the trachea. Phase averaged velocity profiles were calculated in 16 phases of sinusoidal cycle. As a result, velocity fields involving flow separations were measured. This result indicates that the adverse pressure gradient occurs in branch region and curved region of the bronchus model at inspiration part. It is found that the separation flow does not occur at expiration part.