Measurement of Aerodynamic Characteristics Using Cinder Models through Free Fall Experiment

Atmosphere

Takashi Maruyama¹  Meizhi Liu²  Minoru Inoue³  Kansuke Sasaki³  Eisuke Fujita⁴  Masato Iguchi⁵ 

[1] Disaster Prevention Research Institute, Kyoto University, Kyoto 611-0011, Japan;Graduate School of Engineering, Kyoto University, Kyoto 611-0011, Japan;Japan Weather Association, Tokyo 170-6055, Japan;National Research Institute for Earth Science and Disaster Resilience, Ibaraki 305-0006, Japan;Sakurajima Volcano Research Center, Disaster Prevention Research Institute, Kyoto University, Kagoshima 841-1419, Japan;

关键词: cinder model;    free fall experiment;    aerodynamic characteristics;    drag coefficient;    deviation angle between wind direction and wind force direction;   

DOI  :  10.3390/atmos12050608

来源: DOAJ

【 摘 要 】

Rocks ejected from a volcanic eruption often cause loss of lives and structures. Aerodynamic characteristics are needed for evaluating motions of volcanic rocks for the reduction of damage. Falling motions of volcanic rock were measured by using models imitated the configuration of cinders collected at the site of the experiment, Sakurajima volcano. Two types, one with sharp edges and one without sharp edges, were selected as representative of cinder and a sphere was selected as reference model. The falling motions of the models dropped down from a drone were recorded by video camera and a stand-alone measuring system that included a pressure sensor, acceleration and angular velocity sensors in the models. The motion, posture, velocity and acceleration of the model were obtained in order to measure the three-dimensional falling trajectory. The drag and the deviation angle between relative wind direction and wind force direction were examined. The variation of the drag coefficient and the deviation angle with Reynolds number was clarified.

【 授权许可】

Unknown