• Journal of Astronomy and Space Sciences
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• v.29 no.2
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• pp.221-232
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• 2012

We analyzed the manufacturing procedure, specifications, repair history, and details of celestial movements of the water-hammering type $Honsang$ (celestial globe). Results from our study on the remaining $Honsangs$ in China and Japan and on the reconstruction models in Korea were applied to our conceptual design of the water-hammering type $Honsang$. A $Honui$ (armillary sphere) and $Honsang$ using the water-hammering method were manufactured in $Joseon$ in 1435 (the 17th year of King $Sejong$). $Jang$ $Yeong-Sil$ developed the $Honsang$ system based on the water-operation method of $Shui$ $y{\ddot{u}}n$ $i$ $hsiang$ $t'ai$ in China. Water-operation means driving water wheels using a water flow. The most important factor in this type of operation is the precision of the water clock and the control of the water wheel movement. The water-hammering type $Honsang$ in $Joseon$ probably adopted the $Cheonhyeong$ (天衡; oriental escapement device) system of $Shui$ $y{\ddot{u}}n$ $i$ $hsiang$ $t'ai$ in China and the overflow mechanism of $Jagyeongnu$ (striking clepsydra) in $Joseon$, etc. In addition to the $Cheonryun$ system, more gear instruments were needed to stage the rotation of the $Honsang$ globe and the sun's movement. In this study, the water-hammering mechanism is analyzed in the structure of a water clock, a water wheel, the $Cheonhyeong$ system, and the $Giryun$ system, as an organically working operation mechanism. We expect that this study will serve as an essential basis for studies on $Heumgyeonggaknu$, the water-operating astronomical clock, and other astronomical clocks in the middle and latter parts of the $Joseon$ dynasty.

• Journal of Astronomy and Space Sciences
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• v.30 no.3
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• pp.187-192
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• 2013

Honsangui (celestial globe) which is a water-hammering method astronomical clock is recorded in "Juhaesuyong" which is Volume VI of supplement from "Damheonseo", written by Hong Dae-Yong (1731~1783). We made out the conceptual design of Hong Dae-Yong's Honsangui through the study on its structure and working mechanism. Honsangui consist of three rings and two layers, the structure of rings which correspond to outer layer is similar to his own Tongcheonui (armillary sphere) which is a kind of armillary sphere. Honsang sphere which correspond to inner layer depicts constellations and milky way and two beads hang on it as Sun and Moon respectively for realize the celestial motion. Tongcheonui is operated by the pendulum power but Honsangui is operated by water-hammering method mechanism. This Honsangui's working mechanism is the traditional way of Joseon and it was simplified the working mechanism of Shui y$\ddot{u}$n i hsiang t'ai which is a representative astronomical clock of China. This record of Honsangui is the only historical record about the water-hammering method working mechanism of Joseon Era and it provide the study of water-hammering method mechanism with a vital clue.

• International Journal of Air-Conditioning and Refrigeration
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• v.10 no.1
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• pp.19-30
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• 2002

This paper addresses characteristics of compressible flow dynamics inside a pipe with an accumulator and an inlet orifice. It also presents a simple but stable numerical method associated with the accumulator-orifice calculation. In particular, a focus is given to developing a method of finding an optimum design of the accumulator-orifice system (i.e., the accumulator size and the throttle resistance) that gives the most effective dissipation of the water-hammering problem. It is found that there exists indeed an optimum set of parameter values for the most effective dissipation of the wave energy.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.1
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• pp.57-64
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• 1992

A computer program was developed for the prediction of transient flow in a water supply system. where an air chamber is installed to reduce the water hammering. The governing equations based on a characteristic method are solved using a finite difference method. A design process of an air chamber is shown in the present paper considering the effects of the initial air volume and the discharge coefficients of the orifice on the total volume and over-all performance of the chamber.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.453-458
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• 2008

Pump of high lift use to development of a technological level according as a building grow big. Water-Hammer to increase by valve of fast to closing agreeably to pipe laying to accept electronic valve, because by a damage of piping-system and the devil knows injury of vibration. Water-Hammer take a low effect to various method for solve. A New type manufacture develop and testing of pipe line to same to axis use to accumulator for water-Hammer to low effect and liner control of pressure. Impact-pressure of absorption ability and confirmation to decrease of vibration level through to preexistence manufactures and comparative test. Water-hammer and pipe vibration make low of piping system.

• Journal of Astronomy and Space Sciences
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• v.30 no.2
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• pp.113-121
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• 2013

Heumgyeonggaknu is a water-hammering type automatic water clock which was made by Jang Yeong-Sil in 1438. The water clock that is located in Heumgyeonggaknu consists of Suho which is equipped with 2-stage overflow. Constant water wheel power is generated by supplying a fixed amount of water of Suho to Sususang, and this power is transferred to each floor at the same time. The 1st floor rotation wheel of Gasan consists of the operation structure which has the shape of umbrella ribs. The 2nd floor rotation wheel is made so that the 12 hour signal, Gyeong-Jeom signal, and Jujeon constitute a systematic configuration. The 3rd floor rotation wheel is made so that the signal and rotation of Ongnyeo and four gods can be accomplished. Based on the above conceptual design, this paper analyzed the internal signal generation and power transmission of Heumgyeonggaknu.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.45-46
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• 2006

Usual LEO satellite for earth observation use a blowdown hydrazine monopropellant propulsion system for attitude hold and orbit maintenance. For precision control, thruster valve has very short closing time, but this can cause water hammering and pressure surge. Since water hammering and pressure surge can cause damage of propulsion system and ununiform thrust, Thruster valve closing is one of the special concern during satellite propulsion system design. In this paper, an analysis for propellant feed system is conducted using the method of characteristics. The results represent water hammer effect is negligible even at the worst case and pressure surge can be decreased effectively with a trim orifice.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.5
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• pp.388-397
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• 2001

This paper addresses characteristics of compressible flow dynamics inside a pipe with an accumulator and an inlet orifice. It also presents a simple but stable numerical method associated with the accumulator-orifice calculation. In particular, a focus is given to developing a method of finding an optimum design of the accumulator-orifice system (i.e., the accumulator size and the throttle resistance) that gives the most effective dissipation of the water-hammering problem. It is found that there exists indeed an optimum set of parameter values for the most effective dissipation of the wave energy.

• 보존과학연구
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• s.13
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• pp.37-58
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• 1992

Iron artifacts from Busǒ Sansǒng inffered to late Baikjae periodwere studied on the aspects of metallugy. These materials were the largest size ever since excavated. From the analytical results these artifacts were found to be pureiron system without impurities or hypo-eutectoid steel system in below 0.3% in carbon contents. From the content of phosphorus in the range of 0.03∼0.05% as aim purity it was shown that charcoal were used for making these iron artifacts from sponge iron not fusion method. By observing metallugical structure it was found that iron artifacts was manufactured by repetitive folding and hammering forging method and some by heating method for adding carbon with cool water. This method were to improve the quality of the soften steel to harden one. In addition to those above repetitive hammering method eliminated the nonferrous materials such as slag inclusion and remained relatively pure ferrite.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.5
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• pp.638-646
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• 1985

Water hammering in nuclear or thermal power plant condenser cooling water systems in mathematically modeled and numerically analyzed based on the method of characteristics. Effects of variations of the discharge valve operating condition and the system geometry on the hydraulic transients are investigated for the cases when all or one of four pumps are tripped accidently due to loss of offisite power. Effects of ocean waves and tides on the steady-state and the transient operations are also studied. Water column separation in taken into account whenever necessary by means of a simplified physical model.