Polar ships face significant risks from ice accretion on decks,superstructures,and power systems.Ice formation on the power intake system particularly affects vessel stability and safety.While freshwater icing has bee...Polar ships face significant risks from ice accretion on decks,superstructures,and power systems.Ice formation on the power intake system particularly affects vessel stability and safety.While freshwater icing has been extensively researched,comprehensive multi-parameter studies on ice accretion for intake structures remain insufficient.This investigation examines the icing characteristics of the air shroud,a critical component of marine gas turbines,resulting from saltwater droplet freezing.The study utilized a custom-built cyclic ice wind tunnel,with flow field quality verified through Five-hole probe and Hot wire anemometer methods,and droplet field quality validated using Laser,Flowmeter,Ice blade,and Icing calibration grid techniques.The research analyzes ice distribution and thickness on the shroud under varying NaCl concentrations,considering temperature,liquid water content(LWC),and median volume diameter(MVD).The findings reveal that decreased salinity facilitates rime ice formation,resulting in rough ice texture.Temperature reduction,increased LWC,and larger MVD enhanced salinity's influence on ice thickness.The shroud exhibits substantial radial ice accretion,with coverage extending to approximately 90%.These results establish a foundation for further investigation of saltwater icing mechanisms and pioneer icing research in marine gas turbine intake systems.展开更多
Blades are important parts of rotating machinery such as marine gas turbines and wind turbines,which are exposed to harsh environments during mechanical operations,including centrifugal loads,aerodynamic forces,or hig...Blades are important parts of rotating machinery such as marine gas turbines and wind turbines,which are exposed to harsh environments during mechanical operations,including centrifugal loads,aerodynamic forces,or high temperatures.These demanding working conditions considerably influence the dynamic performance of blades.Therefore,because of the challenges posed by blades in complex working environments,in-depth research and optimization are necessary to ensure that blades can operate safely and efficiently,thus guaranteeing the reliability and performance of mechanical systems.Focusing on the vibration analysis of blades in rotating machinery,this paper conducts a comprehensive literature review on the research advancements in vibration modeling and structural optimization of blades under complex operational conditions.First,the paper outlines the development of several modeling theories for rotating blades,including one-dimensional beam theory,two-dimensional plate-shell theory,and three-dimensional solid theory.Second,the research progress in the vibrational analysis of blades under aerodynamic loads,thermal environments,and crack factors is separately discussed.Finally,the developments in rotating blade structural optimization are presented from material optimization and shape optimization perspectives.The methodology and theory of analyzing and optimizing blade vibration characteristics under multifactorial operating conditions are comprehensively outlined,aiming to assist future researchers in proposing more effective and practical approaches for the vibration analysis and optimization of blades.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.U2241270)China Postdoctoral Science Foundation(Grant No.2025M774341)+1 种基金the Heilongjiang Province Postdoctoral Special Funding Project(Grant No.LBHTZ2408)the Outstanding Doctoral Dissertation Funding Project of Heilongjiang in the New Era(Grant No.LJYXL2024-007)。
文摘Polar ships face significant risks from ice accretion on decks,superstructures,and power systems.Ice formation on the power intake system particularly affects vessel stability and safety.While freshwater icing has been extensively researched,comprehensive multi-parameter studies on ice accretion for intake structures remain insufficient.This investigation examines the icing characteristics of the air shroud,a critical component of marine gas turbines,resulting from saltwater droplet freezing.The study utilized a custom-built cyclic ice wind tunnel,with flow field quality verified through Five-hole probe and Hot wire anemometer methods,and droplet field quality validated using Laser,Flowmeter,Ice blade,and Icing calibration grid techniques.The research analyzes ice distribution and thickness on the shroud under varying NaCl concentrations,considering temperature,liquid water content(LWC),and median volume diameter(MVD).The findings reveal that decreased salinity facilitates rime ice formation,resulting in rough ice texture.Temperature reduction,increased LWC,and larger MVD enhanced salinity's influence on ice thickness.The shroud exhibits substantial radial ice accretion,with coverage extending to approximately 90%.These results establish a foundation for further investigation of saltwater icing mechanisms and pioneer icing research in marine gas turbine intake systems.
基金Supported by the National Natural Science Foundation of China under Grant No.52271309Natural Science Foundation of Heilongjiang Province of China under Grant No.YQ2022E104.
文摘Blades are important parts of rotating machinery such as marine gas turbines and wind turbines,which are exposed to harsh environments during mechanical operations,including centrifugal loads,aerodynamic forces,or high temperatures.These demanding working conditions considerably influence the dynamic performance of blades.Therefore,because of the challenges posed by blades in complex working environments,in-depth research and optimization are necessary to ensure that blades can operate safely and efficiently,thus guaranteeing the reliability and performance of mechanical systems.Focusing on the vibration analysis of blades in rotating machinery,this paper conducts a comprehensive literature review on the research advancements in vibration modeling and structural optimization of blades under complex operational conditions.First,the paper outlines the development of several modeling theories for rotating blades,including one-dimensional beam theory,two-dimensional plate-shell theory,and three-dimensional solid theory.Second,the research progress in the vibrational analysis of blades under aerodynamic loads,thermal environments,and crack factors is separately discussed.Finally,the developments in rotating blade structural optimization are presented from material optimization and shape optimization perspectives.The methodology and theory of analyzing and optimizing blade vibration characteristics under multifactorial operating conditions are comprehensively outlined,aiming to assist future researchers in proposing more effective and practical approaches for the vibration analysis and optimization of blades.
