Identification of peak stresses in cardiac prostheses. A comparison of two-dimensional versus three-dimensional principal stress analyses.

摘要: This study assessed the accuracy of using a two-dimensional principal stress analysis compared to three-dimensional in estimating peak turbulent stresses complex flows associated with cardiac prostheses. Three-component, coincident laser Doppler anemometer measurements were obtained steady flow downstream three prosthetic valves: St. Jude bileaflet, Bjork-Shiley monostrut tilting disc, and Starr-Edwards ball cage. Two-dimensional analyses performed identify local stresses. Valves locally exhibited 10-15% underestimation largest measured normal In nearly all flows, shear underestimated by 10-100%. Differences between less than 10% flows. typically values 20%. However, agreement was dependent upon two velocity-components used analysis, observed vary across valve field because structure variation. The use two-component velocity data from misaligned plane maximum mean can underpredict as much 100%.