CAJ | 학술논문

采用有限体积法离散并应用Simple方法对方截面弯曲管道内的纳米粒子传输和沉降进行了数值计算,结果表明Reynolds数和Schmidt数是影响纳米粒子传输和沉降的重要参数.粒子较小时,弯管中轴向速度较大的区域就是粒子的高浓度区域,沉降增强因子最大值出现在外弯侧的中心位置;粒子较大时,截面浓度的梯度值降低,沉降增强因子趋于平均,此时整个截面的粒子平均沉降.弯曲作用对于粒子较大且Dean教也较大时的影响更加明显.
채용유한체적법리산병응용Simple방법대방절면만곡관도내적납미입자전수화침강진행료수치계산,결과표명Reynolds수화Schmidt수시영향납미입자전수화침강적중요삼수.입자교소시,만관중축향속도교대적구역취시입자적고농도구역,침강증강인자최대치출현재외만측적중심위치;입자교대시,절면농도적제도치강저,침강증강인자추우평균,차시정개절면적입자평균침강.만곡작용대우입자교대차Dean교야교대시적영향경가명현.
Transport and deposition of nanoparticles in bend tubes with square cross-section are simulated numerically for different Reynolds numbers and Schmidt numbers.A finite-volume code and the SIMPLE scheme are used to solve the equations.The results show that when the Schmidt number is small,the high axial velocity region is also the high nanoparticle concentration region.The maximum of deposition enhancement factor (DEF) appears at the center of the outside of the bend edge.When the Schmidt number becomes large,the gradient of the nanoparticle concentration on the cross-section decreases,the DEF tends to be uniform.The nanoparticles deposit on the whole cross-section averagely.The influence of the curvature is much more notable for the large nanoparticle when the Dean number is high.