Thongsri, Jatuporn
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Preferred name
Thongsri, Jatuporn
Alternative Name
Thongsri, J.
Main Affiliation
Email
jatuporn.th@kmitl.ac.th
20 results
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Item type:Publication, A simulation of the number of particles trapped by the circulating filter of a hard disk drive and their trajectories(2014-01-01); Pongkom, VanaA transition shear stress transport turbulence model and a discrete phase model of Fluent software were employed to simulate numerically the trajectories of loose particles and the number of them trapped by the circulating filter of a hard disk drive (HDD). The filter was located either at the left or the right of a 2.5 inch dual platter HDD rotating at 7200 rpm. Particles were released from the middle diameter position where four head gimbal assemblies (HGAs) were located. The simulation included airflow and particle trajectories released from any of the four HGAs. The results of this simulation can help determine the efficiency of a circulating filter and its optimal placement. © (2014) Trans Tech Publications, Switzerland. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Development of an industrial ultrasonic cleaning tank based on harmonic response analysis(2019-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Feasibility Study for Installing Machine in Production Line to Avoid Particle Contamination Based on CFD Simulation(2017-11-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Optimum airflow to reduce particle contamination inside welding automation machine of hard disk drive production line(2015-03-01); Welding automation machine (WAM), used for welding minute components to the head gimbal assembly (HGA) of a hard disk drive (HDD), needs to operate in a strictly clean environment. In today’s HDD factories, to prevent airborne particle contamination to the WAM, Fan Filter Units (FFUs) are installed on top of it to supply clean air and blow away outside airborne micro particles, keeping the microenvironment clean. Furthermore, the mass of the clean air should also carry away harmful particles generated inside the microenvironment. In this research, numerical simulation of airflow inside a WAM was performed in order to verify these cleaning functions of the airflow. A transition shear stress transport turbulence model was employed to simulate airflow from the FFUs through and out of the microenvironment. The simulation results showed that the airflow from the FFUs truly performs the two cleaning functions as intended. Moreover, they also revealed that the optimum air speed, the speed resulting in the lowest particle counts, is in the range of 0.35–0.55 m/s. Our findings can be useful for developers who may use FFUs to reduce particle counts in the environment of other types of industrial machinery. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Improved Design of Ultrasonic Cleaning Tank Using Harmonic Response Analysis in ANSYS(2018-06-14) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Successful simulation of airflow in the microenvironment of an assembly automation machine and its implication(2014-01-01); Khaokom, AdisornToday, the hard disk drive (HDD) industry is using assembly automation machine (AAM) to construct head stack assembly (HSA) from smaller parts. AAM needs to operate in a clean environment with very low particle counts. To achieve this end, fan filter Unit (FFU) is used to supply purified air into the environment by filtering out airborne particles from recirculating air. In this study, we investigated numerically the airflow induced by FFUs inside a microenvironment that houses an AAM in an HDD factory. The boundary conditions chosen for simulation were directly derived from the real ambient conditions in this HDD factory. We found that the FFUs not only filter out airborne particles from the air supplied into the microenvironment but also act as a particle blocker, pushing away the nearby particles in the air surrounding the openings of the microenvironment. The findings from this study can be applied to cases where other kinds of machinery need to be protected from airborne particles. © (2014) Trans Tech Publications, Switzerland. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of grain size on ferroelectric films using effective medium theory(2014-01-01)Based on effective medium theory, the temperature dependence of effective dielectric permittivity, ε<inf>e</inf>(T), on the core radius (a) and thickness (t) of nonferroelectric dead layer (DL) on the surface of inhomogeneous grains of ferroelectric film made up of cylindrical ferroelectric grains was theoretically investigated. It was found that ε<inf>e</inf>(T) increases with increasing core radius and decreases with increasing DL thickness. In this study, an equation expressing the relationship among ε<inf>e</inf>, a and t was derived. This equation is useful for preparing ferroelectric film to desired properties. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A Problem of Particulate Contamination in an Automated Assembly Machine Successfully Solved by CFD and Simple Experiments(2017-01-01)Assembly of hard disk drives (HDDs) needs to be done in an automated assembly machine (AAM) virtually free of particulate contamination that can cause them to malfunction. Fan filter units (FFUs) are installed above the AAM to reduce the number of suspended particles in the recirculating air flowing over and around them. At one time, several HDDs were found to be defective. To find out the root cause of this problem, computational fluid dynamics (CFD) was used to investigate the airflow over and around the AAM. It was found that the cause of the high particle counts was improper air speed from the FFUs. The optimal FFUs air speed needed to be in the range of 0.35-0.65 m/s in which the airflow would block out nearby airborne particles and purge away particles generated by the AAM effectively which would, in effect, reduce the particle counts down below the threshold level of class 100 clean room. A few available measurement tools at the factory were then used to perform validating measurements against the simulation results, and the validation was positive. This optimal speed range was implemented at the factory after which the level of contamination was reduced to an acceptable level. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of grain size on effective permittivity of ferroelectric films based on effective medium theory(2014-01-01)Based on effective medium theory, the temperature dependence of effective dielectric permittivity, ε<inf>e</inf>(T), on core radius (a) and thickness (t) of non-ferroelectric dead layer (DL) on the surface of inhomogeneous grains of ferroelectric film made up of cylindrical ferroelectric grains was theoretically investigated. It was found that ε<inf>e</inf>(T) increases with increasing core radius but decreases with increasing DL thickness. In this work, an equation expressing the relationship among εe, a and t was derived. This equation is very useful for the preparation of a ferroelectric film to desired properties. © (2014) Trans Tech Publications, Switzerland. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A CFD investigation of airflow in a hard disk drive production line to detect the cause(s) of contamination and its mitigation(2017-07-02); Kaewkhaw, PolsateContamination exceeds the standards in certain areas within the production line of hard disk drive (HDD) manufacturing, such as in the clean room of a factory. In order to find the cause(s) and solve the problem, we decided to use the computational fluid dynamics (CFD) to simulate the airflow within the production line. The results show the cause of contamination, which is from the exhaust fan installed in the electrical testing machine in the production line of HDD manufacturing, which releases large amounts of particles. To resolve this problem, the CFD results were analyzed to design and create a new cover for the exhaust fan. Once this invention is installed to the electrical testing machine, it can control the airflow to float into other areas that do not affect nor contaminate the product. The factory utilized this research. Other than solving contamination problems that exceed standards, it also saves production costs from purchasing new machines as well.