Article
Chemistry, Multidisciplinary
Jie Xu, Shurong Yu, Xuexing Ding, Haitao Jiang, Lu Li
Summary: This paper investigates the effect of different textures on the sealing performance of compliant foil gas film seals. The results show that the gas volume accommodated by the texture has a greater impact on the sealing performance, and a convergent texture can effectively control the leakage rate. When the texture depth exceeds a certain value, the sealing system may become unstable. The compliant foil seal is well suited to higher-speed service conditions, and the inverted triangular texture shows the best comprehensive sealing performance.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Chemical
Xueliang Wang, Meihong Liu
Summary: This paper analyzes the dynamic performance of compliant foil gas seal with different structure parameters, and obtains the influence rules of parameters such as seal diameter, seal length and gas film thickness on the sealing performance. The results show that suitable structure parameters can improve the stability and dynamic characteristics of compliant foil gas seal.
Article
Engineering, Mechanical
Yuan Chen, Qinggang Wang, Yuntang Li, Xiaolu Li, Bingqing Wang, Jie Jin
Summary: To investigate the influence of hypervelocity gas effects on gas lubrication performance, a modified gas-elastic coupling lubrication theory model is used, taking into account choked flow and inertia effect. The analysis reveals that choked flow significantly increases sealing outlet pressure and reduces flow velocity. The increase in medium pressure and balance film thickness worsens the choking effect and leads to an increase in opening force and a decrease in leakage rate. The inertia effect causes radial flow velocity reduction and wide pressure distribution, especially under high rotational speed and pressure, resulting in a decrease in opening force and leakage rate.
Article
Engineering, Mechanical
Yuan Chen, Kai Chen, Xudong Peng, Bingqing Wang, Xiaolu Li, Jie Jin
Summary: This paper presents a novel bump-type compliant foil face gas seal (BCFFGS) and proposes a theoretical model that combines the Reynolds equation and foil deformation equation to investigate the operation mechanism of BCFFGS. The study compares BCFFGS with rigid surface face gas seal (RSFGS) in terms of film pressure, film thickness, and flow field, and obtains a range of preferred structural parameters that significantly affect the sealing performance of BCFFGS. Numerical results indicate the intrinsic relationships among film pressure, foil deformation, and film thickness for BCFFGS. Furthermore, the performance analysis shows that BCFFGS outperforms RSFGS under the studied parameters. BCFFGS achieves the best sealing performance and stability at the slope ratio of 0.2-0.3, the foil-dam ratio of 1.5-1.8, and the number of cycles of 12-16.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2022)
Article
Engineering, Mechanical
Yuan Chen, Kai Chen, Xudong Peng, Yuntang Li, Xiaolu Li, Bingqing Wang, Jie Jin
Summary: This paper presents the transient elasto-aerodynamically coupling behavior and adaptive mechanism of a bump-type compliant foil face gas seal (BCFFGS) considering the disturbance of film thickness. A numerical solution for the elasto-aerodynamically coupling model of BCFFGS is obtained using the finite difference method based on gas lubrication and elasticity theories. The influence of axial and angular film thickness disturbances on transient sealing performance is analyzed. The results show that the compliant support structure effectively enhances the anti-disturbance capability of the gas film and suppresses large fluctuations of the opening force.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2023)
Article
Chemistry, Physical
Filip Wasilczuk, Pawel Flaszynski, Lukasz Pyclik, Krzysztof Marugi
Summary: This paper analyzes the methods for manufacturing turbine blades, highlighting the potential of manufacturing slots in the shroud region to control shroud leakage flow. A parametric study on bypass slot dimensions is conducted using numerical simulations, showing the most effective dimensions and explaining why they are effective. An interesting finding is that a slot not covering the entire span of the fin is more effective than one that does, due to the creation of additional streamwise vortices.
Article
Engineering, Mechanical
Yuan Chen, Cong Xiong, Yuntang Li, Xiang Li, Xiaofeng Xue, Bingqing Wang, Yuan Gan
Summary: This study focuses on the floating seal dam compliant foil face gas seal (FSD-CFFGS) and compares its dynamic performance with the rigid surface face gas seal (RSFGS) using the coupling method. By solving the seal dynamics equation, transient Reynolds equation, and foil deformation equation, the researchers found that the dynamic performance of FSD-CFFGS is significantly improved compared to RSFGS. They also found that optimizing parameters such as the supporting foil compliance coefficient and spring stiffness can further enhance the dynamic performance.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2023)
Article
Engineering, Aerospace
Qingcai Zhang, Qinqin Wang, Xiaoming Tan, Jingzhou Zhang
Summary: This paper proposes two composite sealing structures to protect the turbine disk cavity and improve sealing efficiency. The results show that rotor-stator interaction, cooling air flow, and the shape of the sealing cavity play important roles in sealing efficiency.
Article
Acoustics
Signe T. Heinemann, Janus W. Jensen, Sebastian von Osmanski, Ilmar F. Santos
Summary: There is no consensus on the best practice for modelling the compliant foil structure of Gas Foil Bearings (GFBs) in the literature. This paper focuses on the modelling of the top foil and compares four different top foil models (with and without gas injection) in terms of steady state analysis efficiency and accuracy. The results show that the model using Euler-Bernoulli beam elements is both computationally efficient and accurate for steady state analysis compared to the model using non-curved shell elements.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Engineering, Aerospace
Filip Wasilczuk, Pawel Flaszynski, Piotr Kaczynski, Ryszard Szwaba, Piotr Doerffer, Krzysztof Marugi
Summary: This paper introduces a passive flow control technique called the air curtain, which reduces leakage through the shroud sealing of a turbine rotor by generating a high velocity jet in the clearance between the seal and the casing using pressure difference between shroud domains. Experimental and numerical investigations show that applying the air curtain can effectively reduce leakage, with reduction effectiveness varying with gap size and reaching up to 15% tested and 20% by simulation. The paper also outlines model simplifications for labyrinth seal flow investigations.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Mechanical
Xinrui Li, Xiaoqiang Fan, Zhenggui Li, Minhao Zhu
Summary: Magnetic fluid seals are widely used for gas and vacuum sealing, but their effectiveness decreases when used for liquid sealing. A novel pole structure with a non-magnetic shaft is proposed, which allows for the observation of the seal failure processes through a hollow transparent shaft. The failure occurs in two stages: leakage channel opening and complete seal leakage, and dynamic failure is influenced by dissolution, extrusion, and interface instability, with the magnetic fluid film becoming unstable and leaking at critical speed. The research uncovers key factors for seal failure and highlights the need for understanding the interplay between design, magnetic fluid properties, and operating conditions to develop efficient liquid seals.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Aerospace
Zeyu Wu, Xiang Luo, Jianqin Zhu, Hang Chen, Jiahua Liu
Summary: The study focused on the windage loss caused by protrusion in a rotor-stator cavity, revealing that the protrusion shape can impact sealing efficiency, a factor often overlooked in previous researches. Experimental investigation of several typical protrusion shapes showed varying degrees of improvement in total pressure and sealing efficiency, with drop shape demonstrating the best overall performance among the eight models tested.
CHINESE JOURNAL OF AERONAUTICS
(2021)
Article
Engineering, Mechanical
Fengming Hu, Qiang He, Weifeng Huang, Yuan Yin, Xue Wen, Ying Liu, Yuming Wang
Summary: This paper proposes a new method for condition monitoring of dry gas seals by manufacturing special monitoring grooves on one side of the dual end face. The characteristics of end-face contact can be detected by an acoustic emission sensor, with the primary characteristic being seven times the motor speed frequency.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Jianwei Cheng, Qiang Fu, Yu Wang, Zhiyuan Ma, Dezhi Ran, Shuping Sheng, Yongzhen Ma
Summary: Gas produced during coal formation is a major safety threat in coal mining operations. However, it also has the potential to be a clean energy source. This paper presents a novel non-coagulant long-term sealing material that effectively plugs gas boreholes, improving gas extraction efficiency.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Geosciences, Multidisciplinary
Sebastian Cardona, Hirofumi Kobayashi, Lesli Wood, Brandon Dugan, Alexei V. Milkov
Summary: Mass transport complexes and their associated deposits are common in deepwater basins. Previously considered undesirable for petroleum exploration, it is now recognized that these deposits can act as source, reservoir, or seal elements. A methodology is proposed to assess the quality of these submarine failure deposits as effective seals, taking into account factors at different scales. Case studies and feedback from exploration companies support the potential of these deposits as effective seals and a valuable play concept.
MARINE AND PETROLEUM GEOLOGY
(2022)
