کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
768136 1462709 2014 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Equilibrium distributions for straight, curved, and immersed boundary conditions in the lattice Boltzmann method
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مکانیک محاسباتی
پیش نمایش صفحه اول مقاله
Equilibrium distributions for straight, curved, and immersed boundary conditions in the lattice Boltzmann method
چکیده انگلیسی


• We design a new versatile boundary condition method for the lattice Boltzmann method.
• We verify the proposed method with four traditional test cases.
• We compare the accuracy of our method to that of two others which are significantly different conceptually.
• Our method provides a gain in accuracy for lower viscosity flows.
• The immersed version of our method produces smooth pressure contours across boundaries.

A versatile velocity boundary condition treatment for the lattice Boltzmann method is proposed. The method can handle straight and curved boundaries, whether immersed or not. It is based on the streaming of equilibrium particle distributions emanating from ghost nodes. The fundamental idea is the location of these ghost nodes, specifically chosen on the lattice to avoid the evaluation of non equilibrium distributions. The methodology considers that the particle collision process time on the ghost nodes is proportional to the distance from the fluid nodes missing distributions. The linear nature of the BGK operator, which relaxes distributions exactly to their equilibrium state when the collision time is equal to the relaxation time, is also a key element. The method is compared to two other classical approaches for boundary condition treatment in the lattice Boltzmann method, on four test cases for which results are available in the scientific literature. Overall, the proposed method is second order accurate, and, when compared to the other two approaches, smaller errors were observed, especially for flows with a shorter relaxation time.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Computers & Fluids - Volume 101, 20 September 2014, Pages 126–135
نویسندگان
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