西南交通大学学报 第 55 卷 第 4 期 2020 年 8 月 JOURNAL OF SOUTHWEST JIAOTONG UNIVERSITY Vol. 55 No. 4 Aug. 2020 ISSN: 0258-2724 DOI：10.35741/issn.0258-2724.55.4.12 Research article Engineering Please select the m ost suitable field of scientific research IMPINGING FLUID IN IMMERSED GRANULAR MATERIAL TO OBTAIN LOCAL FLUIDIZATION FOR BREAKING SEDIMENTATION 将沉浸颗粒材料中的流体撞击到局流态以进行沉降 Eko Yudiyanto a, b, * , I. Nyoman Gede Wardana b , Nurkholis Hamidi b , Denny Widhiyanuriyawan b a Mechanical Engineering Department, Politeknik Negeri Malang Malang, Indonesia, eko.yudianto@polinema.ac.id, eko.yudiyanto@gmail.com b Mechanical Engineering Department, Brawijaya University Malang, East Java, Indonesia, wardana@ub.ac.id, hamidy@ub.ac.id, denny_w@ub.ac.id Received: April 20, 2020 ▪ Review: June 25, 2020 ▪ Accepted: July 30, 2020 This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) Abstract Granular material is the most abundant material type in industry. Efforts to improve the efficiency of handling of granular material are continually ongoing. Sedimentation is one of the problems in transporting this material; when sedimentation occurs, the flow of material is obstructed and requires significant energy to clean the pipelines. The problem of sedimentation in pipes is thus an issue that merits serious attention. To solve the sedimentation problem, it is proposed to use the impinging method, which is a shock flow that is inserted into the granular sediment. This experiment to impinge immersed granular material is proposed to solve this depositional problem. Shooting high-speed fluid in a short time is expected to be one of the methods of preventing sedimentation that occurs in handling granular material. The material used in this experiment varies in granule size: very fine, fine, and medium-sized granules. These experiments provide an overview of post-impinging granular behavior with fluidization movement. For very fine granular size, post-impinging fluid cavity expansion occurs, followed by slow fluidization. This fluidization movement occurs for a long time. For fine granules, fluid cavity formation happens much faster, and fluidization occurs immediately. For medium-sized granules, post-impinging fluidization occurs immediately. To measure the impinging process to produce fluidization, the Reynold Number of Impinging (Re*) is used. The fluidization process occurs at Re* < 4000. The internal fluidization movements occur mainly at Re* values 2000-4000 (i.e. transition regions). Keywords: Sedimentation, Impinging Fluid, Granular Material, Fluidization 摘要 颗粒材料是工业上最丰富的材料类型。不断努力提高粒状材料的处理效率。沉淀是运输这种 材料的问题之一。当发生沉淀时，物质的流动受阻，需要大量的能量来清洁管。因此，管中 的沉淀问题是一个值得引起高度重视的问题。为了解决沉降问题，提出了使用冲击方法，该冲击