Drag Reduction and Vortex-Induced Vibration Suppression Behavior of Longitudinally Grooved Suppression Technology Integral to Drilling Riser Buoyancy Units

Marcollo, Hayden; Potts, Andrew; Johnstone, Daniel; Pezet, Peter; Kurts, Phillip

doi:10.1115/1.4038933

Cited by 5 publications

(1 citation statement)

References 3 publications

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“…There are some other measures, which also sufficiently mitigate the VIV, need to change the entire length of the cylinder, such as Bach-type blades (Zhu et al 2019), groove strips (Wang et al 2019) and control rods (Lu et al 2019). Similar to helical strakes (Xu et al 2018, Chen et al 2019, Takeshi and Tian 2020, surface control bumps (Owen and Bearman 2001), bionic surface inspired by giant arctus (Marcollo et al 2018, Wang et al 2020, plasma actuators (Hebrero et al 2020) and wavy cylinders (Lam andLin 2009, Zou and are also effective on drag reduction and VIV mitigation. In Owen's study, the drag reductions up to 47% were recorded for a circular cross-sectional body with a wavy axis.…”

Section: Introductionmentioning

confidence: 99%

A novel drag reduction and vortex shedding mitigation measure for a circular cylinder in the subcritical regime

Zhang

et al. 2020

Fluid Dyn. Res.

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A novel aerodynamic measure, an arch mounted leeward of a circular cylinder, is proposed to reduce drag and mitigate vortex shedding for a circular cylinder. To confirm the validity of the proposed measure, the aerodynamic forces were measured through a force meter at the end of a cylinder, the wind pressure was measured at seven cross-sections of the cylinder, and elastically mounted cylinders were also tested. The results show that the arch significantly reduces drag and fluctuating lift by mitigating the vortex shedding in the subcritical Reynolds number range when the proper central angle is selected for the arch. The arch creates a higher base pressure at the leeward side and induces a pressure exchange and spanwise axial flow. This influence is extended along the length of the cylinder by the axial flow due to the strong correlation in the wake in the subcritical regime. Therefore, the arch lowers the base pressure and disrupts the formation of vortex shedding.

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Section: Introductionmentioning

confidence: 99%

A novel drag reduction and vortex shedding mitigation measure for a circular cylinder in the subcritical regime

Zhang

et al. 2020

Fluid Dyn. Res.

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Numerical investigation on vortex-induced vibration suppression of the cactus-inspired cylinder with some ribs

et al. 2021

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Vortex-induced vibration (VIV) responses of the cactus-inspired cylinder with some ribs are numerically investigated, and the range of Reynolds number is 8.0 × 103 < Re < 5.6 × 104. The motion equations of VIV response are solved by the Newmark-beta method. The effects of different numbers of ribs (N, N is the number of the ribs) on VIV suppression are investigated in detailed, and six different numbers of ribs (N) include S0 (N = 0), S1 (N = 8), S2 (N = 12), S3 (N = 16), S4 (N = 20) and S5 (N = 24). The peak value of the cross-flow amplitude ratio decreases from 1.50 (S0) to 0.65 (S2), which is reduced by about 56.67%. The peak value of the in-line amplitude ratio decreases from 0.35 (S0) to 0.12 (S2, S3, S4, and S5), which is reduced by about 65.71%. The peak value of the mean drag coefficient decreases from 3.00 (S0) to 2.1 (S2), reduced by about 30.0%. When N = 8, VIV response is enhanced and it can contribute to trigger the large-amplitude or even divergent structural motion, such as galloping. When N ≥ 12, the VIV responses of S2, S3, S4, and S5 are all suppressed. When N ≥ 12, the range of the lock-in region is wider and wider as the number of ribs increase, and the range of lock-in region of S5 (N = 24) is the similar to that of S0 (N = 0). For the cactus-inspired cylinder, the detached boundary-layer is usually formed between two ribs and the smaller vortices are formed between the ribs. And the ribs of the cactus-inspired cylinder destroy the normal boundary-layer separation and reduce the strength of the wake vortex for S2, S3, S4 and S5. However, the reattachment of the boundary layer occurs after the first separation of the boundary layer for S1, which may cause unstable VIV response. Especially, galloping phenomenon may occur in the high Reynolds number for S1. Compared with the separation line of the smooth cylinder (S0), the separation line of the cactus cylinder (S5) obviously develops away from the cylinder and the coupling process of the wake vortex is suppressed.

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Drag Reduction Method of Deep Pine Components in Soda Saline-Alkali Soil for a Smart City

Wang

Feng

Zhang

et al. 2023

Journal of Testing and Evaluation

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The traditional method of deep pine in soda saline-alkali soil has great resistance, so the structure of the deep pine shovel is optimized to reduce the resistance. The deep pine shovel structure model was constructed with bionic technology, and the 3-D bionic model was built with Unigraphics software to imitate the appearance of the paw and toe of the Daurian typhus. The tip of the deep loose shovel imitates the surface structure of the lip base of the head of a dung beetle, which makes the tip of the shovel have good nonstick and wear resistance characteristics. The structural parameters, manufacturing materials, and technology of the spatula tip were determined, and the connection and fixation of the spatula tip and handle were completed by force analysis of the spatula tip and handle. In order to verify the drag reduction effect of the proposed method, a comparative experiment was designed. The experimental results show that the resistance of the designed deep pine shovel is 5,592.8 N when the tillage depth is 25 cm and 7,129 N when the tillage depth is 30 cm. When the tillage speed is 0.2 m/s, the resistance to the deep pine shovel of the drag reduction method in this paper is 521 N. When the tillage speed increases to 1.0 m/s, the resistance of the deep pine shovel in this paper is only 1,035 N. The method in this paper has good drag reduction effect and high application value.

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Drag Reduction and Vortex-Induced Vibration Suppression Behavior of Longitudinally Grooved Suppression Technology Integral to Drilling Riser Buoyancy Units

Cited by 5 publications

References 3 publications

A novel drag reduction and vortex shedding mitigation measure for a circular cylinder in the subcritical regime

A novel drag reduction and vortex shedding mitigation measure for a circular cylinder in the subcritical regime

Numerical investigation on vortex-induced vibration suppression of the cactus-inspired cylinder with some ribs

Drag Reduction Method of Deep Pine Components in Soda Saline-Alkali Soil for a Smart City

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