• The KSFM Journal of Fluid Machinery
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• v.9 no.6 s.39
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• pp.29-34
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• 2006

Propeller type pump has been widely used for pumping water in agricultural and manufacturing industry. Since a propeller type pump contains a screw impeller inside a circular casing, the numerical analysis becomes complex. However, the accurate prediction of viscous flow is essential for computing hydrodynamic performances. To analysis the flow and the performance of the propeller type pump, the present work has solved 3D incompressible RANS equations on the multiblocked grid. From the present calculation, small amount of flow separation was shown near hub and the flow was recovered to nearly uniform inflow after one diameter downstream. Torque and thrust coefficient were computed and compared with experiments.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.488-499
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• 1996

A propeller type mistblower was designed and manufactured. The machine consisted of a 770 millimeters diameter propeller driven by the power take off of a tractor. It delivered 26,400 cubic meters of air per hour and has the outlet speed about 180 kilometers per hour. Spray liquid was injected at 30 bars pressure through hollow cone type nozzles which were located around the air outlet of the machine bya poston type pump. Power consumption of the machine was found to be 12.46 kilowatts and the effective forward travel speed was about 2.7 kilometers per hour. Upon spraying mango trees, it was shown that the density of spray partices was about 100 microns and consumed 3.12 liters per tree. Working speed in 6 meters row spacing mango orchard was about one hectare per hour.

• The Journal of Korea Robotics Society
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• v.8 no.1
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• pp.51-57
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• 2013

Recently, the number of jellyfish has been rapidly grown because of the global warming, the increase of marine structures, pollution, and etc. The increased jellyfish is a threat to the marine ecosystem and induces a huge damage to fishery industries, seaside power plants, and beach industries. To overcome this problem, a manual jellyfish dissecting device and pump system for jellyfish removal have been developed by researchers. However, the systems need too many human operators and their benefit to cost is not so good. Thus, in this paper, the design, implementation, and experiments of autonomous jellyfish removal robot system, named JEROS, have been presented. The JEROS consists of an unmanned surface vehicle (USV), a device for jellyfish removal, an electrical control system, an autonomous navigation system, and a vision-based jellyfish detection system. The USV was designed as a twin hull-type ship, and a jellyfish removal device consists of a net for gathering jellyfish and a blades-equipped propeller for dissecting jellyfish. The autonomous navigation system starts by generating an efficient path for jellyfish removal when the location of jellyfish is received from a remote server or recognized by a vision system. The location of JEROS is estimated by IMU (Inertial Measurement Unit) and GPS, and jellyfish is eliminated while tracking the path. The performance of the vision-based jellyfish recognition, navigation, and jellyfish removal was demonstrated through field tests in the Masan and Jindong harbors in the southern coast of Korea.