Experimental discussion on basic characteristics of flow electrification between dielectric liquids and metal wire meshes

A new apparatus has been developed for experimental study of basic characteristics of flow electrification phenomenon. Electricity produced on metal wire meshes as liquid flows over them was measured using the apparatus. In order to examine the effects of channel shape and solid-liquid combination, meshes with four different opening areas as well as ones made of four different kinds of metals were tested for machine oil and fluorine compound (FC) a test liquids. The measurements have revealed how the examined physical factors dominate the production of electric charge. The findings are summarized as follows; ( 1 ) electric charge produced on the metal mesh increases with an increasing liquid velocity flowing over the mesh. ( 2 ) The charge production also depends on the rate of liquid velocity change. In other words, the acceleration of flow is another dominating factor in flow electrification. ( 3 ) The longer the perimeter of a mesh is, the larger the produced charge becomes at the same velocity of liquid through the mesh. ( 4 ) Machine oil charges brass, copper and stainless steel negative, but aluminum positive, whereas FC charges all these metals positive. In electrification between machine oil and these metals, the amount of charge is the largest for brass, while the smallest for aluminum. FC produces most charge on stainless steel and least on brass and copper.