The parabolized stability equation (PSE) was derived to study the linear stability of particle-laden flow in growing Blasius boundary layer. The stability characteristics for various Stokes numbers and particle concen...The parabolized stability equation (PSE) was derived to study the linear stability of particle-laden flow in growing Blasius boundary layer. The stability characteristics for various Stokes numbers and particle concentrations were analyzed after solving the equation numerically using the perturbation method and finite difference. The inclusion of the nonparallel terms produces a reduction in the values of the critical Reynolds number compared with the parallel flow. There is a critical value for the effect of Stokes number, and the critical Stokes number being about unit, and the most efficient instability suppression takes place when Stokes number is of order 10. But the presence of the nonparallel terms does not affect the role of the particles in gas. That is, the addition of fine particles (Stokes number is much smaller than 1) reduces the critical Reynolds number while the addition of coarse particles (Stokes number is much larger than 1) enhances it. Qualitatively the effect of nonparallel mean flow is the same as that for the case of plane parallel flows.展开更多
The nonlinear stability problem in nonparallel boundary layer flow fortwo-dimensional disturbances was studied by using a newly presented method called ParabolicStability Equations (PSE). A series of new modes generat...The nonlinear stability problem in nonparallel boundary layer flow fortwo-dimensional disturbances was studied by using a newly presented method called ParabolicStability Equations (PSE). A series of new modes generated by the nonlinear interaction ofdisturbance waves were tabu-lately analyzed, and the Mean Flow Distortion (MFD) was numericallygiven. The computational techniques developed, including the higher-order spectral method and themore effective algebraic mapping, increased greatly the numerical accuracy and the rate ofconvergence. With the predictor-corrector approach in the marching procedure, the normalizationcondition was satisfied, and the stability of numerical calculation could be ensured. With differentinitial amplitudes, the nonlinear stability of disturbance wave was studied. The results ofexamples show good agreement with the data given by the DNS using the full Navier-Stokes equations.展开更多
基金Project supported by the National Natural Science Foundation ofChina (No. 10372090) and the Doctoral Program of Higher Educationof China (No. 20030335001)
文摘The parabolized stability equation (PSE) was derived to study the linear stability of particle-laden flow in growing Blasius boundary layer. The stability characteristics for various Stokes numbers and particle concentrations were analyzed after solving the equation numerically using the perturbation method and finite difference. The inclusion of the nonparallel terms produces a reduction in the values of the critical Reynolds number compared with the parallel flow. There is a critical value for the effect of Stokes number, and the critical Stokes number being about unit, and the most efficient instability suppression takes place when Stokes number is of order 10. But the presence of the nonparallel terms does not affect the role of the particles in gas. That is, the addition of fine particles (Stokes number is much smaller than 1) reduces the critical Reynolds number while the addition of coarse particles (Stokes number is much larger than 1) enhances it. Qualitatively the effect of nonparallel mean flow is the same as that for the case of plane parallel flows.
文摘The nonlinear stability problem in nonparallel boundary layer flow fortwo-dimensional disturbances was studied by using a newly presented method called ParabolicStability Equations (PSE). A series of new modes generated by the nonlinear interaction ofdisturbance waves were tabu-lately analyzed, and the Mean Flow Distortion (MFD) was numericallygiven. The computational techniques developed, including the higher-order spectral method and themore effective algebraic mapping, increased greatly the numerical accuracy and the rate ofconvergence. With the predictor-corrector approach in the marching procedure, the normalizationcondition was satisfied, and the stability of numerical calculation could be ensured. With differentinitial amplitudes, the nonlinear stability of disturbance wave was studied. The results ofexamples show good agreement with the data given by the DNS using the full Navier-Stokes equations.
