2014 Volume 14 Issue Special_Issue Pages s94-s100
A cleaning device equipped with a special nozzle containing triangular cavities is developed to add high-frequency turbulence to the impinging jet flow. In order to clarify the removal mechanism of fine particles adhered to a wall by van der Waals force, a numerical simulation is performed to estimate various removal forces acting on the particle. Here we examine the effect of the force due to a pressure gradient fluctuation of the impinging jet on removal performance. The numerical results show that viscous drag has the greatest influence, while the pressure gradient force is enhanced by the cavities and has a remarkable effect on the removal of particles larger than 1.5 μm. The numerical results qualitatively correspond to the tendency of measured removal rates for 1.6 μm particles.
