Based on the similarities and differences between artistic thinking and design thinking, insight into the development trend of contemporary art

Guoyu wang(왕국유),YoungHwan Pan(반영환) 한국디자인학회 2019 한국디자인학회 학술발표대회 논문집 Vol.2019 No.5

몰입식 설치미술에서 색조의 역할

Wang Guoyu,Pan Younghwan 한국서비스디자인학회 2019 한국서비스디자인학회 학술대회자료집 Vol.2019 No.1

DMB+, a General Data Transmission Technique

( Guoyu Wang ),( Hongsheng Zhang ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.5

Developed from Digital Multimedia Broadcasting (DMB), DMB+ changes the application focus fundamentally. The plus symbol “+” indicates that DMB+ is no longer for digital radio/videos, instead it works as a general data transmission technique. The merits of wireless transmission, broad coverage, high quality, information security and low building/maintenance cost make DMB+ suitable for a wide range of applications with numerous terminals and users, such as public information release, alarm and administration etc. The concept of DMB+ base station enables DMB+ to be used in building independent networks and for remote control and management, as well as for Industry 4.0. DMB+ will access into a new field that till now has been dominated by communication techniques, will open a huge commercial opportunity.

Numerical study on the influence of interphase interaction in sheet/cloud cavitating flows around a 2D hydrofoil

Guanghao Chen,Guoyu Wang,Biao Huang,Changli Hu,Taotao Liu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.3

We investigated the influence of interphase interaction on unsteady sheet/cloud cavitating flows around a 2D hydrofoil numerically. Inthe computations, the homogeneous (without the consideration of interphase interaction) and inhomogeneous (with the consideration ofinterphase interaction) multiphase flow models are used, respectively. The inhomogeneous model assumes that both phases co-exist atevery point in the flow field and each phase is governed by its own set of conservation laws. The exchanges of mass, interphase dragforce and momentum transfer induced by interphase mass transfer are treated explicitly as transfer terms. The results show that the distributionsof interphase drag force and momentum transfer induced by mass transfer are highly related with the velocity difference of twophases and interphase mass transfer rate, respectively. Without the consideration of interphase interaction, the over-prediction of turbulenteddy viscosity in the rear of attached cavity causes the reentrant jet to lose its momentum and becomes too weak to cut across thecavity sheet. However, when considering the interphase interaction, the predicted turbulent kinetic energy in the rear of attached cavitycan be reduced considerably; thus, turbulent eddy viscosity drops significantly in this region, and the reentrant jet becomes much stronger,so typical cloud cavitation shedding occurs. Compared with those predicted without the consideration of interphase interaction, a betteragreement with experimental results concerning the time evolution of cavity shape, time-averaged lift/drag coefficient, frequency andmean u-velocity profiles is obtained with the consideration of interphase interaction.

Three-dimensional unsteady cavitating flows around an axisymmetric body with a blunt headform

Changli Hu,Guoyu Wang,Guanghao Chen,Biao Huang 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.3

We investigated the three-dimensional characteristics in the unsteady cavitating flow over an axisymmetric body with a blunt headform. A high-speed video camera was used to visualize the cavitating flow structures. A modified PANS (Partially-averaged Navier-Stokes) turbulence model coupled with Kubota cavitation model was used to simulate the time-evolution process of the unsteady cavitatingflows. The finite-time Lyapunov exponent (FTLE) and Lagrangian coherent structures (LCS) methods are applied to investigate thethree-dimensional flow patterns. The results show that the numerical method is capable of simulating the unsteady cavitating flow forcapturing the attached cavity with maximum-length, the cavity break-off and U-type shedding, in accordance with the qualitative featuresobserved in the experiment. Three-dimensional characteristics are extremely impressive in the unsteady cavitating flows. The re-entrantflows originate from different circumferential positions at the closure region of the attached cavity, and move upstream at differentspeeds. Moreover, substantial circumferential motions in the unsteady cavitating flow are found based on Lagrangian trajectories, and itis reasonably deduced that the U-type shedding cavity is primarily induced by the effect of re-entrant flow motions consisting of movingupstream and circumferential flows as well.

Thermal Effects on Cryogenic Cavitating Flows around an Axisymmetric Ogive

Shi, Suguo,Wang, Guoyu Korean Society for Fluid machinery 2010 International journal of fluid machinery and syste Vol.3 No.4

Cavitation in cryogenic fluids generates substantial thermal effects and strong variations in fluid properties, which in turn alter the cavity characteristics. In order to investigate the cavitation characteristics in cryogenic fluids, numerical simulations are conducted around an axisymmetric ogive in liquid nitrogen and hydrogen respectively. The modified Merkle cavitation model and energy equation which accounts for the influence of cavitation are used, and variable thermal properties of the fluid are updated with software. A good agreement between the numerical results and experimental data are obtained. The results show that vapor production in cavitation extracts the latent heat of evaporation from the surrounding liquid, which decreases the local temperature, and hence the local vapor pressure in the vicinity of cavity becomes lower. The cavitation characteristics in cryogenic fluids are obtained that the cavity seems frothy and the cavitation intense is lower. It is also found that when the fluid is operating close to its critical temperature, thermal effects of cavitation are more obviously in cryogenic fluids. The thermal effect on cavitation in liquid hydrogen is more distinctively compared with that in liquid nitrogen due to the changes of density ratio, vapour pressure gradient and other variable properties of the fluid.

Physical and Numerical Investigation of Cavitating Flow-Induced Vibration of a Flexible Hydrofoil

Qin Wu,Guoyu Wang,Biao Huang 한국유체기계학회 2017 International journal of fluid machinery and syste Vol.10 No.3

The objective of this paper is to investigate the flow-induced vibration of a flexible hydrofoil in cavitating flows via combined experimental and numerical studies. The experiments are presented for the modified NACA66 hydrofoil made of POM Polyacetate in the closed-loop cavitation tunnel and the numerical investigations are performed using a hybrid coupled fluid structure interaction model. The results showed that with the decreasing of cavitation number, the vibration magnitude increases dramatically for the cloud cavitation and declines for the supercavitation. The cloud cavitation development strongly affects the vibration response, with the main frequency of the vibration being accordance with the cavity shedding frequency and other two frequencies corresponding to the bending and twisting frequencies.

Physical and Numerical Investigation of Cavitating Flow-Induced Vibration of a Flexible Hydrofoil

Wu, Qin,Wang, Guoyu,Huang, Biao Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.3

The objective of this paper is to investigate the flow-induced vibration of a flexible hydrofoil in cavitating flows via combined experimental and numerical studies. The experiments are presented for the modified NACA66 hydrofoil made of POM Polyacetate in the closed-loop cavitation tunnel and the numerical investigations are performed using a hybrid coupled fluid structure interaction model. The results showed that with the decreasing of cavitation number, the vibration magnitude increases dramatically for the cloud cavitation and declines for the supercavitation. The cloud cavitation development strongly affects the vibration response, with the main frequency of the vibration being accordance with the cavity shedding frequency and other two frequencies corresponding to the bending and twisting frequencies.

Experimental investigation of inception cavitating flows around axisymmetric bodies with different headforms

Changli Hu,Guoyu Wang,Xuede Wang,Biao Huang 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.7

Experiments have been performed to study the inception cavitation phenomena in the separated flows adjacent to two axisymmetric bodies whose forebodies are blunt and conical respectively. A high-speed video camera was used to visualize the dynamic process of incipient cavitation, and the PIV (Particle imaging velocimetry) technology was applied to measure the velocity field, the vorticity and turbulence fluctuations under non-cavitation and inception cavitation conditions. Observations suggest that incipient cavities around the two axisymmetric bodies have the similar onset appearance but different development patterns and cycles with different inception cavitation index. Also, it is found that incipient cavities are always located within the separated vortex upstream the reattachment point during the whole dynamic process, and the scale of separation vortex greatly influences the positions where incipient cavities generate and collapse. Measures of the turbulence fields show that the distribution of vorticity can be changed by unsteady incipient cavities, and inception cavitation causes slight uniformity of velocity in shear layer and conspicuous increase of turbulent fluctuations. Compared to that of the conical headform, inception cavitation around the blunt headform presents more vortical traits and turbulence fluctuations.

The structures of unsteady cavitation shedding flow around an axisymmetric body with a blunt headform

Changli Hu,Xuede Wang,Guoyu Wang,Youquan Cao 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.1

The objective of this paper is to investigate the cavity shedding dynamics in unsteady cavitating flows around an axisymmetric body with a blunt headform. A high-speed video camera is used to record the cavity evolution process. The numerical simulations are performed based on the homogenous method coupled with a modified PANS (Partially-averaged Navier-Stokes) turbulence model and Zwart cavitation model. The results show that the predicted time-evolution process of cavity agree fairly well with the corresponding experimental data for two different cavitation numbers ( s = 0.7 and s = 0.6 ). Compared to that of s = 0.6 , the cavity shedding behavior of s = 0.7 presents more fluctuations and instabilities. To elucidate the different shedding structures, the Lagrangian coherent structures (LCS) and particle trajectory methods are also utilized here. It is found that the particle tracers respectively demonstrate the cavity shedding behaviors of conjunction at s = 0.6 and rolling up at s = 0.7 . Moreover, the LCS distributions vary with the timeevolution of vortex structures. The particle trajectories can illustrate the upstream and downstream vortex structures connect together at s = 0.6 but separate at s = 0.7 , which highly consistent with the cavity shedding behaviors.