• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.228-236
• /
• 2011

The analysis of the performance and the internal flow according to various numerical models used for the interior ballistics has been conducted. The internal flow has been mainly affected by the drag model. As results, oscillations of the pressure differences between the breech and the shot base has been reduced with a deceased drag of the propellant. The major performance of the interior ballistics has no relation to the models using Nusselt number for heat transfer coefficient. The negative pressure difference without the heat transfer of the propellant has not been shown.

• 유체기계공업학회:학술대회논문집
• /
• 2001.11a
• /
• pp.400-403
• /
• 2001

In this study, commercial CFD code, i.e, CFX-4.3 is used to analyze the flow field and to calculate pressure differences in an orifice flowmeter. Four numerical schemes and five turbulence models are tested. Hybrid scheme and Reynolds stress model show the best performance. Chosen scheme and turbulence model are applied to predict pressure differences through the orifice for the diameter ratios, 0.3, 0.5, and 0.7. And, the results are compared with the experimental data. The results show that the calculation error is inversely proportional to the diameter ratio, and is proportional to the mass flow rate.

• 한국전산유체공학회:학술대회논문집
• /
• 2011.05a
• /
• pp.41-45
• /
• 2011

Pressure drops of two-phase flow in a pipe according to particle shapes have been calculated and analyzed. The numerical analysis for 3 cases of Reynolds number has been conducted for each particle shape. In case of the cylinder shape, the particles had been assumed to be randomly distributed for each Reynolds number. The results have been averaged and compared to those of the case of the ball shape. Additionally, pressure drops of ball and cylinder shapes has been compared to the result of Ergun's equation.

• 한국전산유체공학회:학술대회논문집
• /
• 1997.10a
• /
• pp.143-148
• /
• 1997

Differential pressure Venturi cone flowmeter is an advanced flowmeter which has many advantages such as wide range of measurement, high accuracy, excellent flow turndown ratio, low headless, and short installation pipe length requirement, etc. Like other differential pressure flowmeter, Venturi cone flowmeter uses the law of energy conservation, but its shape and position make it perform better than others. The cone acts as its own flow conditioner and mixer, fully conditioning and mixing the flow prior to measurement. For the analysis, we use Reynolds-averaged Navier-Stokes equations and $k-{\omega}$ turbulence model. The equations are fully trans-formed in the computational coordinates, the pressure-velocity coupling is made through SIMPLER algorithm, and the equations are discretized using analytic solutions of the linearized equations(Finite Analytic Method). At the end of the paper, using the result of analysis, We propose a new shape of cone with the hope of drag reduction and high performance.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.860-864
• /
• 2001

Today's industrialized plants are required to reduce SOx emitted from stacks at factories, utility power stations, etc. For this purpose, flue gas desulfurization (FGD) system is installed and gas-gas heater (GGH) is used to play a vital role to reheat the wet treated gas from FGD. The sector plates are located at cold and hot sides of gas gas heater. They serve as sealing to prevent mixing treated and untreated gases. Therefore, the deformation of the sector plate due to its dead weight and gas pressure should be considered as major factor for the sector plate design.

• 유체기계공업학회:학술대회논문집
• /
• 2005.12a
• /
• pp.150-157
• /
• 2005

Generally, the flow hunting is observed in almost all of the orifice meters but the intensity of the flow hunting is different at each metering system. So, we were getting some Questions as follows; why such a difference occurs and whether it influence to metering error rate or not. To investigate the flow hunting characteristics, we are trying to examine the flow characteristics around the orifice meter when the transient flow or pressure is generated at after the PCV(Pressure Control Valve) by 3D CFD method. And we have compared numerical results with experimental results at M - PCV station in order to clarify the relations with both the metering-pipeline diameter and flow rate. Finally, we can show some major factors influencing to the flow hunting and propose some correcting scheme of the flow hunting equation.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.15 no.3
• /
• pp.241-249
• /
• 2012

Performance analysis of the interior ballistics has been conducted using the 1-D numerical code called IBcode according to the various conditions such as length of ignition-gas injector, amount of ignition-gas, mass of projectile, and drag force of projectile. In case of the length of ignition-gas injector, the 25~100 % of the full-injector length has been considered as well as the mass & mass flow of the ignition-gas. The mass of the projectile 5~70 kg and its drag force of 0~69 MPa have been also considered. Variables such as breech & base pressure, negative differential pressure and muzzle velocity for the performance analysis have been sorted, too. Firing conditions for the optimal performance have been investigated through these variables.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.877-880
• /
• 2011

A coaxial swirl/shear injector using GCH4/LOx as propellants was degisned and manufactured. Flow analysis by Fluent was performed to decide the number of orifice and the rear shapes of inlet orifice etc. Flow rate of the injector was measured according to differential pressure and uniformity of injector's spray pattern was confirmed by a patternator. The results showed that the difference of flow rate was around 10% and the spray angle of oxidizer was $66^{\circ}$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.658-661
• /
• 2011

A coaxial swirl/shear injector using GCH4/LOx as propellants was degisned and manufactured. Flow analysis by Fluent was performed to decide the number of orifice and the rear shapes of inlet orifice etc. Flow rate of the injector was measured according to differential pressure and uniformity of injector's spray pattern was confirmed by a patternator. The results showed that the difference of flow rate was around 10% and the spray angle of oxidizer was $66^{\circ}$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.11a
• /
• pp.107-110
• /
• 2009

A basic design for a Technical Development Model (TDM) of liquid oxygen lines from the turbopump exit to the oxidizer valves of the combustion chamber and the gas generator was conducted to develop a turbopump-fed liquid rocket engine. The TDM is composed of straight lines, elbows, bellows, a branch, an orifice, flanges and a heat insulator. Materials were determined by consideration of operation conditions, weight constraint and manufacturing procedures. The size and the location of each component were determined by flow analysis of the required flowrate and the pressure loss. Basic designs of the components were conducted by consideration of the operating temperature and the maximum expectation operating pressure. The safety factors were evaluated by structural analysis of design of each component.