流速与压强对马尾松木材气体渗透性的影响(英文)

在1.3×10-6到1.0×10-5m3·s-1的流速条件下,测量马尾松的纵向空气渗透系数.在所使用的流速范围内,空气流速与样品两端的空气压强差呈现线形与非线形的关系,其非线形的分量随空气流速或压强差的增大而增强.空气流速或压强差对样品的纵向空气渗透系数有影响,在6个所测量的试样中,5个试样的纵向空气渗透系数最大值与最小值的相对差在3.1%到5.7%之间,而1个试样的相对差则达到了34.2%.根据本文的研究结果,应该使用不同的气体流速(气体压强差)测量木材样品的气体渗透系数,用所测得的这些结果的几何平均值或以流速与压强差为权重的加权平均值作为样品的气体渗透系数,并指明测量气体渗透系数时不同的气体流速或压强差的范围.

Effect of Flow Rate and Pressure Difference on Determination of Air Permeability of Masson Pine

Longitudinal air permeability of Masson Pine(Pinus massoniana)specimens was determined at different flow rates from 1.3×10-6 to 1.0×105 m3·s-1.The flow rate exhibited a linear and nonlinear relationship with the pressure difference between the ends of specimen within the investigated range.The nonlinear flow component increases with increasing of pressure difierence or flow rate.The flow rate(or the pressure difference)had innuenee on the measured values of the longitudinal air permeability of each specimen.Of six investigated specimens,the relative difference between the maximum and minimum of the longitudinal air permeability was from 3.1%to 5.7%for five specimens.while one specimen had the relative difference as high as 34.2%.It suggested that measurement of air permeability of specimen should be made at different flow rates.Air permeability of wood should be taken from arithmetic or weighed average of values from measurement at different flow rates or different pressure differences.Moreover.the range of flow rates or the pressure differences should also be presented together with the air permeability of wood.