• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.1
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• pp.32-40
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• 1993

Flow fields in model engine cooling passages are studied numerically by using TURBO-3D program, a finite volume based 3-D turbulent flow program adopting a general body fitted coordinate system. The effects of exit position on mass flow rate at each gasket hole are examined for a model cooling passage in order to understand the flow distribution inside the water jacket. The results of the present study can be applied to the design of high performance, high reliability engine.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.496-500
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• 1996

An air flow measurement device is proposed. The thermal characteristic of a semiconductor element is adopted as a cooling parameter of thermal convection rate. The difference between forced convection and natural convection of two Zener diodes results enough difference in temperature. Experiment at various air flow conditions shows the measuring capability of the air flow in a duct. This measuring device has some merits, such as a reliability n hard field condition, simple circuit for signal processing, small volume of the element, less air flow resistance, independance of various ai temperature. The experimental result shows that it is an exact and usefull air flow measurement device.

• Journal of the Korea Society for Simulation
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• v.7 no.2
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• pp.17-32
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• 1998

The flow fields in Gas Bubble Driven Circulation Systems were numerically analyzed. In various gas flow rate and bubble size, the flow characteristics were predicted. Eulerian-Eulerian approach was used for the formulation of both the continuous and dispersed phases. The modification of the general purpose computer program PHOENICS code was employed to predict the mean flow fields, turbulent characteristics, gas dispersion, volume fraction. The predicted shows very satisfactory agreement with experimental results for all regions of ladle. The results are of interest in the design and operation of wide variety of material processing.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.998-1003
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• 2003

Ultrasonic flow metering(UFM) technology is being received much attention from a variety of industrial fields to exactly measure the flow rate. The UFM has much advantage over other conventional flow meter systems, since it has no moving parts, and offers good accuracy and reliability without giving any disturbances to measure the flow rate, thereby not causing pressure losses in the flow fields. In the present study, 3-dimensional, unsteady, compressible Navier-Stokes equations are solved by a finite volume scheme, based upon the second order upwind scheme for spatial derivatives and the multi-stage Runge-Kutta integral method for time derivatives. In order to simulate multi-path ultrasonic flow meter, an excited pressure signal is applied to three different locations upstream, and the pressure signals are received at three different locations downstream. The mean flow velocities are calculated by the time difference between upstream and downstream propagating pressure signals. The obtained results show that the present CFD method simulates successfully ultrasonic meter gas flow and the mean velocity measured along the chord near the wall is considerably influenced by the boundary layers.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.74-79
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• 2011

This study was accomplished to evaluate the performance of Multi Effect Distillation(MED) for solar thermal desalination system. It was designed Multi effect distillation with $3m^3/day$ capacity and Shell&Tube type heat exchanger. Also, The effective heat transfer of Shell&Tube heat exchanger was used Cu(90%)-Ni(10%) corrugated tube. The parameters relating to the performance of Multi Effect Distillation are known as hot water flow rate. The experimental conditions for each parameters were $18^{\circ}C$ for sea water inlet temperature, $6m^3/hour$ sea water inlet volume flow rate, $75^{\circ}C$ for hot water inlet temperature, 2.4, 3.6, and $4.8m^3/hour$ for hot water inlet volume flow rate, respectively. The results are as follows, Development for Multi effect distillation was required about 40kW heat and 35kW cooling source to produce $3m^3/day$ of fresh water. And, Performance ratio of Development Multi effect distillation was about 2.0191.

• Journal of the Korean Solar Energy Society
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• v.31 no.1
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• pp.1-7
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• 2011

This study was accomplished to evaluate the performance of Multi Effect Distillation(MED) for solar thermal desalination system. It was designed Multi effect distillation with $3m^3$/day capacity and Shell&Tube type heat exchanger. Also, The effective heat transfer of Shell&Tube heat exchanger was used Cu(90%)-Ni(10%) corrugated tube. The parameters relating to the performance of Multi Effect Distillation are known as hot water flow rate. The experimental conditions for each parameters were $18^{\circ}C$ for sea water inlet temperature, $6m^3$/hour sea water inlet volume flow rate, $75^{\circ}C$ for hot water inlet temperature, 2.4, 3.6, and $4.8\;m^3$/hour for hot water inlet volume flow rate, respectively. The results are as follows, Development for Multi effect distillation was required about 40kW heat and 35kW cooling source to produce $3m^3$/day of fresh water. Based on the results of this study, It makes possible to secure economics of desalination system with solar energy which is basically needed development of high efficiency fresh water generator.

• Structural Engineering and Mechanics
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• v.62 no.2
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• pp.163-170
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• 2017

This study presents a particle-wall filtration model for predicting the particle motion behavior in a typical rotational flow field-filtration in blower system of cooker hood. Based on computational fluid dynamics model, air flow and particles has been simulated by Lagrangian-particle/ Eulerian-gas approaches and get verified by experiment data from a manufacturer. Airflow volume, particle diameter and local structure, which are related to the particle filtration has been studied. Results indicates that: (1) there exists an optimal airflow volume of $1243m^3/h$ related to the most appropriate filtration rate; (2) Diameter of particle is the significant property related to the filtration rate. Big size particles can represent the filtration performance of blower; (3) More than 86% grease particles are caught by impeller blades firstly, and then splashed onto the corresponding location of worm box internal wall. These results would help to study the micro-particle motion behavior and evaluate the filtration rate and structure design of blower.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.3
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• pp.933-944
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• 1996

In this paper, two new techniques, the pattern filling and the refined flow field regeneration, based on the finite element method and Eulerian mesh advancement approach have been developed to analyze incompressible viscous flow with free surfaces. The gorerning equation for flow analysis is Navier-Stokes equation including inertia and gravity effects. The penalty and Newton-Raphson methods are used effectively for finite element formulation. The flow front surface and the volume inflow rate are calculated using the pattern filling technique to select an adequate pattern among five filling patterns at each quadrilateral control volume. By the refined flow field regeneration technique, the new flow field which renders better prediction in flow surface shape is generated and the velocity field at the flow front part is calculated more exactly. Using the new thchniques to be developed, the dam-breaking problem has been analyzed to predict flow phenomenon of fluid and the predicted front positions versus time have been compared with the reported experimental result.

• KSBB Journal
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• v.4 no.2
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• pp.177-184
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• 1989

In separating mycelia from antibiotic fermentation broths, high permeate flux was obtained by cross-flow filtration using modified regenerated cellulose membrane. The flux was increased most effectively by increasing the flow rate. There existed a critical mycelium density (about 20% PMV) at which the highest flux was observed. In a batchwise concentration of the fermentation broth, the system suffered from a severe fouling problem, which was relieved drastically by applying diafiltration technique, although it increased the permeate volume. A combined concentration/diafiltration process was ideal in keeping relatively high flux together with a high product recovery yield. The best result was obtained by starting diafiltration after concentrating the broth to 20% PMV. By doing so, a 98% product recovery yield was achieved in the shortest time while keeping the permeate volume at a minimum level.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.229-239
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• 2008

Most algorithms for detecting incidents have been developed under the premise that congestion must happen whenever an incident occurs. For that reason, the performance of these algorithms could not be guaranteed in cases where congestion did not happen due to traffic operations with low flows despite the occurrence of an incident. The objective of this paper is to develop an automatic incident detection algorithm using a new diagram that can reliably detect the incident under various conditions of traffic operations including a low volume state. Compared with the McMaster Algorithm, the proposed algorithm in this paper was evaluated with three different cases in which the incidents occur in traffic operations with a low volume state, a relatively high volume state, and a recurrent congestion state. It is shown that the new algorithm has a capability to identify the flow characteristics of incidents for all the three cases and is much better than McMaster algorithm in terms of detection rate and false alarm rate.