Lycopodium spore impacts onto surfaces

Experiments on oblique impact of Lycopodium spores with dry surfaces in the presence of adhesion were carried out. The experimental results are compar ed with those of stainless steel microsphere impact onto the same types of substrate surfaces. Three parameters are analyzed, the coefficient of resti tution, the impulse ratio and the normalized kinetic energy loss and are us ed to represent the impact results. The comparisons show that the complex s urface profile of a spore has a remarkable effect on impact response. The c onjunction of the roughness of both the microparticle and the substrate mak e the impact mechanics even more complicated. (C) 2000 Elsevier Science Ltd . All rights reserved.