• Wind and Structures
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• v.35 no.1
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• pp.1-20
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• 2022

This research work presents an experimental study's outcomes to reveal the impact of an O-ring on the flow control over a sphere placed in a turbulent boundary layer. The investigation is performed quantitatively and qualitatively using particle image velocimetry (PIV) and dye visualization. The sphere model having a diamater of 42.5 mm is located in a turbulent boundary layer flow over a smooth plate for gap ratios of 0≤G/D≤1.5 at Reynolds number of 5 × 10³. Flow characteristics, including patterns of instantaneous vorticity, streaklines, time-averaged streamlines, velocity vectors, velocity fluctuations, Reynolds stress correlations, and turbulence kinetic energy (), are compared and discussed for a naked sphere and spheres having O-rings. The boundary layer velocity gradient and proximity of the sphere to the flat plate profoundly influence the flow dynamics. At proximity ratios of G/D=0.1 and 0.25, a wall jet is formed between lower side of the sphere and flat plate, and velocity fluctuations increase in regions close to the wall. At G/D=0.25, the jet flow also induces local flow separations on the flat plate. At higher proximity ratios, the velocity gradient of the boundary layer causes asymmetries in the mean flow characteristics and turbulence values in the wake region. It is observed that the O-ring with various placement angles (𝜃) on the sphere has a considerable alteration in the flow structure and turbulence statistics on the wake. At lower placement angles, where the O-ring is closer to the forward stagnation point of the sphere, the flow control performance of the O-ring is limited; however, its impact on the flow separation becomes pronounced as it is moved away from the forward stagnation point. At G/D=1.50 for O-ring diameters of 4.7 (2 mm) and 7 (3 mm) percent of the sphere diameter, the -ring exhibits remarkable flow control at 𝜃=50° and 𝜃=55° before laminar flow separation occurrence on the sphere surface, respectively. This conclusion is yielded from narrowed wakes and reductions in turbulence statistics compared to the naked sphere model. The O-ring with a diameter of 3 mm and placement angle of 50° exhibits the most effective flow control. It decreases, in sequence, streamwise velocity fluctuations and length of wake recovery region by 45% and 40%, respectively, which can be evaluated as source of decrement in drag force.

• Journal of Haehwa Medicine
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• v.9 no.1
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• pp.513-545
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• 2000

I. Introduction Bi(痺) means blocking. It can reach at the joints or muscles or whole body and make pains. Numbness and movement disorders. BiJeung can be devided into SilBi and HeoBi. In SilBi there are PungHanSeupBi, YeolBi and WanBi. In HeoBi, there are GiHyeolHeoBi, EumHeoBi and YangHeoBi. The common principle for the treatment of BiJeung is devision of the chronic stage and the acute stage. In the acute stage, BiJeung is usually cured easily but in the chronic stage, it is difficult. In the terminal stage, BiJeung can reach at the internal organs. BiJeung is one kind of symptoms making muscles, bones and jonts feel pain, numbness or edema. For example it can be gout or SLE etc. Many famous doctors studied medical science by their fathers or teachers. So the history of medical science is long. So I studied ${\ll}Bijeungjujip{\gg}$. II. Final Decision 1. BanSuMun(斑秀文) thought that BiJeung can be cured by blocking of blood stream. So he insisted that the important thing to cure BiJeung is to improve the blood stream. He usually used DangGuiSaYeokTang(當歸四逆湯), DangGuiJakYakSanHapORyeongSan, DoHong-SaMulTang(桃紅四物湯), SaMyoSanHapHeuiDongTang and HwangGiGyeJiOMulTang. 2. JangGeonBu(張健夫) focused on soothing muscles and improving blood seam. So he used many herbs like WiRyeongSeon(威靈仙), GangHwal(羌活), DokHwal(獨活), WooSeul(牛膝), etc. Especially he pasted wastes of the boiled herbs. 3. OSeongNong(吳聖農) introduced four rules to treat arthritis. So he usually used SeoGak-SanGaGam(犀角散加減), BoYanHwanOTang(補陽還五湯), ODuTang(烏頭湯), HwangGiGyeJiOMulTang. 4. GongJiSin thought disk hernia as one kind of BiJeung. And he said that Pung can hurt upper limbs and Seup can hurt lower limbs. He used to use GyeJiJakYakJiMoTang(桂枝芍藥知母湯). 5. LoJiJeong(路志正) introduced four principles to treat BiJeung. He used BangPungTang(防風湯), DaeJinGuTang) for PungBi(風痺), OPaeTang(烏貝湯) for HanBi(寒痺), YukGunJaTang(六君子湯) for SeupBi(濕痺) and SaMyoTang(四妙湯), SeonBiTang(宣痺湯), BaekHoGaGyeTang(白虎加桂湯) for YeolBi(熱痺). 6. GangChunHwa(姜春華) discussed herbs. He said SaengJiHwang(生地黃) is effective for PungSeupBi and WiRyungSun(威靈仙) is effective for the joints pain. He usually used SipJeonDaeBoTang(十全大補湯), DangGuiDaeBoTang(當歸大補湯), YoukGunJaTang(六君子湯) and YukMiJiHwanTang(六味地黃湯). 7. DongGeonHwa(董建華) said that the most important thing to treat BiJeung is how to use herbs. He usually used CheonO(川烏), MaHwang(麻黃) for HanBi, SeoGak(犀角) for YeolBi, BiHae) or JamSa(蠶沙) for SeupBi, SukJiHwang(熟地黃) or Vertebrae of Pigs for improving the function of kidney and liver, deer horn or DuChung(杜沖) for improving strength of body and HwangGi(黃?) or OGaPi(五加皮) for improving the function of heart. 8. YiSuSan(李壽山) devided BiJeung into two types(PungHanSeupBi, PungYeolSeupBi). And he used GyeJiJakYakJiMoTang(桂枝芍藥知母湯) for the treatment of gout. And he liked to use HwanGiGyeJiOMulTangHapSinGiHwan 枝五物湯合腎氣丸) for the treat ment of WanBi(頑痺). 9. AnDukHyeong(顔德馨) made YongMaJeongTongDan(龍馬定痛丹)-(MaJeonJa(馬錢子) 30g, JiJaChung 3g, JiRyong(地龍) 3g, JeonGal(全蝎) 3g, JuSa(朱砂) 0.3g) 10. JangBaekYou(張伯臾) devided BiJeung into YeolBi and HanBi. And he focused on improving blood stream. 11. JinMuO(陳茂梧) introduced anti-wind and dampness prescription(HoJangGeun(虎杖根) 15g, CheonChoGeun 15g, SangGiSaeng(桑寄生) 15g, JamSa(蠶絲) 15g, JeMaJeonJa(制馬錢子) 3g). 12. YiChongBo(李總甫) explained basic prescriptions to treat BiJeung. He used SinJeongChuBiEum(新定推痺陰) for HaengBi(行痺), SinJeongHwaBiSan(新定化痺散) for TongBi(痛痺), SinJeongGaeBiTang(新定開痺湯) for ChakBi(着痺), SinJeongCheongBiEum(新定淸痺飮) for SeupYeolBi(濕熱痺), SinRyeokTang(腎瀝湯) for PoBi(胞痺), ORyeongSan for BuBi(腑痺), OBiTang(五痺湯) for JangBi(臟痺), SinChakTang(腎着湯) for SingChakByeong(腎着病). 13. HwangJeonGeuk(黃傳克) used SaMu1SaDeungHapJe(四物四藤合制) for the treatment of a acute arthritis, PalJinHpPalDeungTang(八珍合八藤湯) or BuGyeJiHwangTangHapTaDeungTang(附桂地黃湯合四藤湯) for the chronic stage and ByeolGapJeungAekTongRakEum(鱉甲增液通絡飮) for EumHeo(陰虛) 14. GaYeo(柯與參) used HwalRakJiTongTang(活絡止痛湯) for shoulder ache, SoJongJinTongHwalRakTank(消腫鎭痛活絡湯) for YeolBi(熱痺), LiGwanJeolTang(利關節湯) for ChakBi(着痺), SinBiTang(腎痺湯) for SinBi(腎痺) and SamGyoBoSinHwan(三膠補腎丸) for back ache. 15. JangGilJin(蔣길塵) liked to use hot-character herbs and insects. And he used SeoGeunLipAnTang(舒筋立安湯) as basic prescription. 16. RyuJangGeol(留章杰) used GuMiGangHwalTang(九味羌活湯) and BangPungTang(防風湯) at the acute stage, ODuTang(烏頭湯) or GyeJiJakYakJiMoTang(桂枝芍藥知母湯) for HanBi of internal organs, YangHwaHaeEungTang(陽和解凝湯) for HanBi, DokHwalGiSaengTang(獨活寄生湯), EuiYiInTang(薏苡仁湯) for SeupBi, YukGunJaTang(六君子湯) for GiHeoBi(氣虛痺) and SeongYouTang(聖兪湯) for HyeolHeoBi(血虛痺). 17. YangYuHak(楊有鶴) liked to use SoGyeongHwalHyelTang(疏經活血湯) and he would rather use DoIn(桃仁), HongHwa(紅花), DangGui(當歸), CheonGung(川芎) than insects. 18. SaHongDo(史鴻濤) made RyuPungSeupTang(類風濕湯)-((HwangGi 200g, JinGu 20g, BangGi(防己) 15g, HongHwa(紅花) 15g, DoIn(桃仁) 15g, CheongPungDeung(靑風藤) 20g, JiRyong(地龍) 15g, GyeJi(桂枝) 15g, WoSeul(牛膝) 15g, CheonSanGap(穿山甲) 15g, BaekJi(白芷) 15g, BaekSeonPi(白鮮皮) 15g, GamCho(甘草) 15g).