On drag coefficient of supercritical water cross-flow past cylinder biomass particel at low reynolds

The super criti cal wa ter gasi fi ca tion of bio mass tech nol ogy is a prom is ing ap proach for the ef fi cient and clean con ver sion of wet-bio mass to hy dro gen-rich gas pro duc tion. Many of the bio mass ma te ri als are of rod like shape and gasified in super criti cal wa ter fluidized bed. So the par ti cle-fluid two-phase flow be hav iors in sider super criti cal wa ter fluidized bed are of great im por tance. Con strained by the ex treme op er at ing con di tion, nu mer i cal meth ods, such as the Eu ler-Eu ler method and Eu ler-Lagrange method, are used to study the flow be hav iors in side the super criti cal wa ter fluidized bed. As the ac cu racy of these meth ods are de pended on the drag force model and there is lit tle in ves ti ga tion on that at super criti cal con di tion, this work is fo cused on the drag co ef fi cient of cyl in der bio mass par ti cle with dif fer ent ra tio of length to di am e ter. The sim u lated re sults show that there is no dif fer ence for the drag co ef fi cient of a cer tain par ti cle at dif fer ent con di tion when the Reynolds num ber is same. The vari a tion ten dency of the pres sure and vis cous drag co ef fi cient with Reynolds number and the ra tio of length to di am e ter is also given in this pa per.