http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Optimum Design for an Air Current Pulverizing Blade Using the Computational Fluid Dynamics
Gun-hoi Kim(김건회),Han-bit Kim(김한빛) 한국기계가공학회 2020 한국기계가공학회지 Vol.19 No.8
In the air current pulverizing type grinding method, the blade wings fitted inside a casing are rotated at a high speed to generate a cornering air current, which facilitates the collision of materials with one another, leading to the pulverizing phenomenon. In contrast to mechanical grinding, grit pulverizing leads to fine grinding and less acid waste and degeneration of the material. Moreover, this approach prevents the loss of nutritional value, while allowing the milling grain to have an excellent texture. However, the existing air current pulverizing type machines consist of prefabricated blades, which cannot be rotated at a speed higher than 5,000 rpm. Consequently, the grinding process becomes time consuming with a low productivity. To overcome these problems, in this study, the shape and structure of the air current pulverizing type wings were optimized to allow rapid grinding at more than 8,000 rpm. Moreover, the optimal design for the ripening parts for the air current pulverizing type device was determined by performing a computational fluid dynamics analysis based on airflow analyses to produce machinery that can grinding materials to the order of micrometers.
Prototype Product Based on the Functional Test of ANG Fuel Vessel Applied to Composite Carbon Fiber
Gun-Hoi KIM(김건회) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.3
Recently, an automobile market used to natural gas has emerged as fast-growing as the several countries, who holds abundant natural fuel resources, has promoted to supply the national agency for an automobile car. LNG fuel vessel is more efficient in another way as the energy density is high, but it requires a high technology and investment to maintain extreme low temperature. CNG fuel vessel are relatively low-cost alternative to LNG, but poorly economical in terms of energy density as well as showing safety issues associated with compressed pressure. The development of adsorbed natural gas (ANG) has emerged as one of potential solutions. Therefore, it is desirable to reduce the weight of vessel by applying light-weighed a composite carbon fiber in order to response to the regulation of CO₂ emission. Herein, this study make the prototype ANG vessel not only based on the optimal design and analysis of material characteristic but also based on the shape design, and it suggest a new type for the composite carbon fiber vessel which verified functional test. Moreover, the detail shape design is analyzed by a finite element analysis, and its verifies the ANG vessel.
Optimal Shape Design of ANG Fuel Vessel Applied to Composite Carbon Fiber
Gun-Hoi Kim(김건회) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.1
The development of adsorbed natural gas (ANG) has emerged as one of potential solutions. It is desirable to reduce the weight of vessel by applying light-weighed a composite carbon fiber in order to response to a egulation of CO2 emission. Through understanding of a composite carbon fiber, and material characteristic of a composite carbon fiber is required in order for better application of a reduction of weight and an analysis of material characteristic. Herein, this study suggest the composite carbon fiber vessel applied to the characteristic of carbon fiber, and it decides the preliminary shape based on the test of material characteristic for ANG vessel applied to a composite carbon fiber, and its basic shape calculate through on the netting theory. Moreover, the detail shape design is analyzed by a finite element analysis, and in the stage of detail sahp design and analysis of stress was performed on the typical shape using a finite element analysis, and the result of preliminary design was verified.
김건회(Gun-Hoi Kim),최승훈(Seung-Hun Choi),서정덕(Jung-Duck So) 한국기계가공학회 2007 한국기계가공학회 춘추계학술대회 논문집 Vol.2007 No.-
In developing new generation vehicles, the fuel cell hybrid vehicle has become more important as environmental standards become more stringent. This paper details the Fuel Cell Hybrid Radio Control Car (FCHRC) with proton exchange membrane fuel cell stack(75×55×65㎜, 6V, 5A) and a secondary battery(7.4V, 2A) charged up by a solar cell(61㎜ x 110㎜, 1.7V, 450㎃). The design work of the FCHRC was made progress by CATIA modeling & assembling before manufacturing it. In this paper, we will focus on the automatic conversion of a power source between the PEMFC and the secondary battery, and finding the optimum conditions (temperature, humidity, airflow rate and hydrogen pressure) through thousands of performance tests in the humidity-temperature program controller. Included are diagrams of the dynamo, fitting the model for the performance test, that we constructed specifically for this research, to turn out the hybrid control system having the efficiently automatic conversion in the different modes (accelerated motion, uniformly accelerated motion, steeply accelerated motion, decelerated motion). The purpose is that the models and data from the experiments we conducted will contribute to the ongoing development of the fuel cell hybrid car.
서정덕(Jung-Duk Seo),이성구(Seong-Ku Lee),김건회(Gun-hoi Kim) 한국기계가공학회 2006 한국기계가공학회 춘추계학술대회 논문집 Vol.2006 No.-
The hydraulic/pneumatic pressure products are applied widely in current industrial area such as in the automation of products assembly, automation of equipment assembly, high-tech machine tool, aircraft, and train, and as the industry development is on progress, the development of the hydraulic/pneumatic pressure products is necessary and it is required in every industrial area. This research developed a position control system of the pneumatic cylinder using a pneumatic cylinder, four two-port valves, two three-port valves, two pressure valve, a check valve, two proximity sensors, and a program logic controller (PLC) to minimize the allowable error on the position control of pneumatic cylinder system and to develop a pneumatic cylinder valve system for further study. The maximum air pressure used for the position control test was 5 ㎏/cm2 and the displacement accuracy of the pneumatic cylinder was measured using a dial gauge. The supply and discharge air pressure and the length of the stroke of the pneumatic cylinder were controlled and set before experiment. The test of the position control of the pneumatic cylinder was carried out 50 times and replicated three times at each condition of the supply and discharge air pressure (2.5/3.5, 3.0/4.0, 3.5/4.5, and 4.0/5.0 ㎏/cm2) and selected stroke length of the pneumatic cylinder. The accuracy of the position control of the pneumatic cylinder increased as the supply and discharge air pressure increased at the stroke length was fixed as 133 ㎜, and increased as the stroke length increased with the fixed supply and discharge air pressure of 3.5/4.5 ㎏/cm2 of the pneumatic cylinder. The most accurate position control of the pneumatic cylinder (i.e., standard deviation of 0.01 ㎜) was obtained at the supply and discharge air pressure of 4.0/5.0 ㎏/cm2 and the stroke length of 170 and 190 ㎜.