• Journal of Magnetics
• /
• v.16 no.3
• /
• pp.276-280
• /
• 2011

This paper presents a non-destructive evaluation study on a radiator with cooling fins as a complex shaped specimen. Radiator structures are used in various heat exchangers, such as automobiles, air conditioners and refrigerators. An eddy current testing method, namely multi-frequency excitation and spectrogram method (MFES), was employed to detect a defect on the radiator tube surrounded by cooling fins. Overall, experimental results suggested that the influence of cooling fin is not as noticeable as that of the defect signals.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2001.05a
• /
• pp.44-48
• /
• 2001

Tube hydroforming technology has increased dramatically, mainly by automotive industry in europe and the americas. It is required tube formability, optimized with regard to tribological factors and specially designed die and presses. In this process has many important parameters as expansion ratio of a tube, axial feeding, internal pressure and preforming low pressure. The following paper discusses to combine forming factors and expectation of manufacture problem by hydroforming of automotive radiator support member.

• Journal of the Korean Society of Safety
• /
• v.8 no.4
• /
• pp.16-20
• /
• 1993

The combined effect of increased pressure/temperature and the reduced material thicknesses act to increase the stress on the radiator componets. The design life of the radiator is influenced by the cyclic stresses and corrosion, which act to weaken the materials, radiator mechanical failure occurs when a tube or solder Joint ruptures, causing coolant loss or insufficient heat rejection. Therefore, in this study, through strain measurement of the tubes in copper/brass radiator, the strain distribution of the tubes in radiator as function of temperature and pressure is obtained.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.8
• /
• pp.1046-1055
• /
• 2000

The flow and thermal phenomena in flat tubes of radiator are analyzed numerically. To predict the characteristics of heat transfer and pressure drop, the flow analysis program for three-dimensional complex geometry is developed, which adopted an non-staggered grid system and Cartesian velocities as dependent variables of the momentum equations. Using the developed program, the effect of tube specifications on the heat transfer characteristics is investigated for various flat tubes. From this study, the following results are obtained; (1) For the same hydraulic diameter($D_h{\doteq}5.2$mm), the Nusselt numbers of three basic modeis(D, J, and H-model) are 8.71, 8.92, and 10.58, respectively, and the pressure drops of D-, J-, and H-model are predicted as $-3.08{\times}10^{-2}\;Pa,\;-3.12{\times}10^{-2}\;Pa,\;and\; -3.98{\times}10^{-2}$ Pa, (2) In case of the same flat tube specification, the fins must be brazed at upper tube surface because the heat is more vividly transferred. Therefore, it is found that the H- model is the most effective tube as a heat exchanger and these results are used as a fundamental data for the design of tube.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.5
• /
• pp.398-410
• /
• 2001

The flow and heat transfer characteristics for three-dimensional mixed convection flows in a radiator flat tube with U--shaped grooves are analyzed numerically. The flow and temperature fields are calculated by using the modified SIMPLE algorithm for irregular geometry. One tube specification among the various flat tube exchangers is recommended by considering the heat transfer and pressure drop. The effects of variation of coolant flow conditions and external air conditions on the flow and the thermal characteristics for the selected tube are investigated. the results show that inlet velocity of coolant flow is the very important factor in heat transfer and pressure drop, and top side is better position than the others as fin cleave to tube.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.1153-1158
• /
• 2009

The performance of louver-finned flat-tube and fin & tube radiators for computer CPU liquid cooling were experimentally investigated. In this study, 7 samples of radiators with different shape and pass number (1, 2, 10) were tested in a wind tunnel. The experiments were conducted under the different air velocity range from 1 to 4 m/s. The water flow rate through a pass was 1.2 LPM. Inlet temperatures of air and water were $20^{\circ}C$ and $30^{\circ}C$ respectively. It was found that the best performance was observed in the louver-finned flat-tube sample considering pressure drop and heat transfer coefficient.

• Proceedings of the SAREK Conference
• /
• 2007.11a
• /
• pp.258-263
• /
• 2007

The performance of louver-finned flat-tube radiators for computer CPU liquid cooling were experimentally investigated. In this study, 5 samples of louver-finned flat-tube radiators with different width size (19mm, 24mm), tube hole (1, 9) and pass number (1, 2, 5) were tested in a wind tunnel. The experiments were conducted under the different air velocity ranging from 1 to 5 m/s. The water flow rate through a pass was 1.7 LPM. Inlet temperatures of air and water were $20^{\circ}C$ and $30^{\circ}C$ respectively. The results showed that the best performance in the 24mm sample considering pressure drop and heat transfer coefficient.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2000.04a
• /
• pp.181-188
• /
• 2000

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.23 no.1
• /
• pp.1-7
• /
• 2011

The performance of louver-finned flat-tube and fin and tube radiators for computer CPU liquid cooling was experimentally investigated. In this study, 7 samples of radiators with different shape and pass number (1, 2, 10) were tested in a wind tunnel. The experiments were conducted under the different air velocity ranged from 1 to 4 m/s. The water flow rate through a pass was 1.2 LPM. Inlet temperatures of air and water were $20^{\circ}C$ and $30^{\circ}C$ respectively. It was found that the best performance was observed in the louver-finned flat-tube sample considering pressure drop and heat transfer coefficient.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.4
• /
• pp.58-67
• /
• 2003

An automotive engine cooling system is closely related with overall engine performances, such as reduction of fuel consumption, decrease of air pollution, and increase of engine life. Because of complex reaction between each component, the direct experiment, using a vehicle, takes high cost, long time, and slow response to the system change. Therefore, a computer simulation would provide the designer with an inexpensive and effective tool for design, development, and optimization of the engine cooling system over a wide range of operating conditions. In this work, it has been predicted the thermal performance of the engine cooling system in cases of stationary mode, constant speed mode, and city-drive mode by mathematical modelling of each component and numerical analysis. The components are engine, radiator, heater, thermostat, water pump, and cooling fans. Since the engine model is the most important, that is divided into eight sub-sections. The volume mean temperature of eight sub-sections are simultaneously calculated at a time. For detail calculation, the radiator and heater are also divided into many sub-sections like control volumes in finite difference method. Each sub-section is assumed to consist of three parts, coolant, tube with fin, and air. Hence it has been developed the simulation program that can be used in case of design and system configuration changes. The overall performance results obtained by the program were desirable and the time-traced tendencies of the results agreed fairly well with those of actual situations.