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A Study on the Development of Mathematical Model of Three-stage Flow Control Valve
Khan, Haroon Ahmad,Kang, Chang Nam,Yun, So Nam The Korean Society for Fluid Power and Constructio 2018 드라이브·컨트롤 Vol.15 No.2
In this study, the theory of fluid mechanics and dynamics is used to build a mathematical model for a three-stage flow control valve. The significance of the study is that the mathematical model can easily be used to study the effect of different design parameters on the performance of the valve. The geometry of the valve and the properties of the fluid were used in this study to determine the variation in the performance of the valve when varying the magnetic force on the pilot spool. While a linearization technique is not used to solve the developed model, the solution of the mathematical model is found in the time domain by simulation of the equations using a software package. The results indicate that if the developed mathematical model is solved for the different values of magnetic force, the valve behaves linearly; the valve is thus called the proportional flow control valve.
Modeling and Simulation of an EPPR Valve Coupled with a Spool Valve
Haroon Ahmad Khan,윤소남 사단법인 유공압건설기계학회 2019 드라이브·컨트롤 Vol.16 No.2
EPPR (Electro-hydraulic Proportional Pressure Reducing) valves are pressure control valves. In this study, an independent metering valve (IMV), which is a combination of a spool valve opened and closed with the help of an EPPR valve, was discussed. The overall performance of the valve (IMV) was obtained by the respective modeling and simulation of the system. The valve investigated in this study is to be used for independent metering of hydraulic excavator actuator e.g. boom, arm, bucket etc. To design the model, continuity equations and force balance equations were used. The set of differential equations were then simulated in Simulink using ODE45 option in the configuration toolbox. The valve has to be able to control the flow rate going in and out of the cylinder separately, which is why the particular configuration was needed and selected.
A Study on the Development of Mathematical Model of Three-stage Flow Control Valve
Haroon Ahmad Khan,강창남,윤소남 사단법인 유공압건설기계학회 2018 드라이브·컨트롤 Vol.15 No.2
In this study, the theory of fluid mechanics and dynamics is used to build a mathematical model for a three-stage flow control valve. The significance of the study is that the mathematical model can easily be used to study the effect of different design parameters on the performance of the valve. The geometry of the valve and the properties of the fluid were used in this study to determine the variation in the performance of the valve when varying the magnetic force on the pilot spool. While a linearization technique is not used to solve the developed model, the solution of the mathematical model is found in the time domain by simulation of the equations using a software package. The results indicate that if the developed mathematical model is solved for the different values of magnetic force, the valve behaves linearly; the valve is thus called the proportional flow control valve.
A Review of Rear Axle Steering System Technology for Commercial Vehicles
Haroon Ahmad Khan(하룬 아흐마드 칸),So-Nam Yun(윤소남),Eun-A Jeong(정은아),Jeong-Woo Park(박정우),Chung-Mok Yoo(유충목),Sung-Min Han(한성민) 유공압건설기계학회 2020 드라이브·컨트롤 Vol.17 No.4
This study reviews the rear or tag axle steering system’s concepts and technology applied to commercial vehicles. Most commercial vehicles are large in size with more than two axles. Maneuvering them around tight corners, narrow roads, and spaces is a difficult job if only the front axle is steerable. Furthermore, wear and tear in tires will increase as turn angle and number of axles are increased. This problem can be solved using rear axle steering technology that is being used in commercial vehicles nowadays. Rear axle steering system technology uses a cylinder mounted on one of rear axles called a steering cylinder. Cylinder control is the primary objective of the real axle steering system. There are two types of such steering mechanisms. One uses master and slave cylinder concept while the other concept is relatively new. It goes by the name of smart axle, self-steered axle, or smart steering axle driven independently from the front wheel steering. All these different types of steering mechanisms are discussed in this study with detailed description, advantages, disadvantages, and safety considerations.
Modeling and Simulation of an EPPR Valve Coupled with a Spool Valve
Khan, Haroon Ahmad,Yun, So-Nam The Korean Society for Fluid Power and Constructio 2019 드라이브·컨트롤 Vol.16 No.2
EPPR (Electro-hydraulic Proportional Pressure Reducing) valves are pressure control valves. In this study, an independent metering valve (IMV), which is a combination of a spool valve opened and closed with the help of an EPPR valve, was discussed. The overall performance of the valve (IMV) was obtained by the respective modeling and simulation of the system. The valve investigated in this study is to be used for independent metering of hydraulic excavator actuator e.g. boom, arm, bucket etc. To design the model, continuity equations and force balance equations were used. The set of differential equations were then simulated in Simulink using ODE45 option in the configuration toolbox. The valve has to be able to control the flow rate going in and out of the cylinder separately, which is why the particular configuration was needed and selected.
Khan, Waseem Ahmad,Haroon, Hiba The Honam Mathematical Society 2019 호남수학학술지 Vol.41 No.1
In the current investigation, we obtain the generating function for Hermite-based degenerate Bernoulli polynomials attached to ${\chi}$ of higher order using p-adic methods over the ring of integers. Useful identities, formulae and relations with well known families of polynomials and numbers including the Bernoulli numbers, Daehee numbers and the Stirling numbers are established. We also give identities of symmetry and additive property for Hermite-based generalized degenerate Bernoulli polynomials attached to ${\chi}$ of higher order. Results are supported by remarks and corollaries.
DEGENERATE BERNOULLI NUMBERS AND POLYNOMIALS ASSOCIATED WITH DEGENERATE HERMITE POLYNOMIALS
Haroon, Hiba,Khan, Waseem Ahmad Korean Mathematical Society 2018 대한수학회논문집 Vol.33 No.2
The article is themed to classify new (fully) degenerate Hermite-Bernoulli polynomials with formulation in terms of p-adic fermionic integrals on $\mathbb{Z}_p$. The entire paper is designed to illustrate new properties in association with Daehee polynomials in a consolidated and generalized form.
정은아,Haroon Ahmad Khan,윤소남,이기윤 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.75 No.10
In this study, a flow analysis and a fluid-solid interaction analysis were performed on a hollow fiber membrane module used for dehumidification of a pneumatic system. To ensure the reliability of the flow analysis results, we performed the dehumidification experiment at a temperature of 30 ◦ C and a relative humidity(RH) of 30% on a module with a similar to that of the analyses. shape only the part containing hollow fiber membranes was considered. Results of the dehumidification experiments were compared with the results of the flow analysis. The results of dehumidification experiments and the flow analysis had a difference of approximately 5%, and although the five models had different grid numbers, the results of flow analysis showed a difference of about 1% in the dehumidification efficiency ensuring the accuracy. A one-way fluid-solid interaction analysis with various materials was performed. From the result, we found that the baffle having the largest shape deformation was the one made of polyethylene material, which was then subjected to a 2-way fluid-solid interaction at 0.53 bar, 1 bar, 5 bar, and 10 bar. The fluid flow and the dehumidification characteristics were determined for different shapes of the deformed baffle. Finally, the effects of three types of flow paths based on the positions of the inlet and the outlet on the baffle deformation and the dehumidification efficiency were studied. We found that dehumidification efficiency was highest when inlet and outlet were positioned in a straight line.