The current research of wind turbine drivetrain is mainly concentrated in dynamic characteristics of gearbox with a specific suspension of main shaft, such as one-point and two-point suspension. However, little attent...The current research of wind turbine drivetrain is mainly concentrated in dynamic characteristics of gearbox with a specific suspension of main shaft, such as one-point and two-point suspension. However, little attention is paid to the e ects of these suspension configurations on the dynamic responses of wind turbine gearbox. This paper investigates the influences of suspension configurations of main shaft on the dynamic characteristics of drivetrain. For evaluating the dynamic behaviors of drivetrain with multi-stage transmission system more realistically, a dynamic modeling approach of drivetrain is proposed based on Timoshenko beam theory and Lagrange's equation. Considering the flexibility and di erent suspension configurations of main shaft, time-varying mesh sti ness excitation, time-varying transmission error excitation and gravity excitation, etc., a three-dimensional dynamic model of drivetrain is developed, and the dynamic responses of drivetrain are investigated. Results show that with the one-point suspension of main shaft, the resonance frequencies in gearbox, especially at the low-speed stage, obviously shift to the higher frequency range compared to the gearbox without main shaft, but this trend could be inversed by increasing main shaft length. Meanwhile, the loads in main shaft, main shaft bearing and carrier bearing are greatly sensitive to the main shaft length. Hence, the load sharing is further disrupted by main shaft, but this e ect could be alleviated by larger load torque. Comparing to the one-point suspension of main shaft, there occurs the obvious load reduction at the low-speed stage with two-point suspension of main shaft. However, those advantages greatly depend on the distance between two main bearings, and come at the expense of increased load in upwind main shaft unit and the corresponding main bearing. Finally, a wind field test is conducted to verify the proposed drivetrain model. This study develops a numerical model of drivetrain which is able to evaluate the e ects of di erent suspension configurations of main shaft on gearbox.展开更多
Compared with most flowers where the showy part comprises specialized leaves(petals)directly subtending the reproductive structures,most Zingiberaceae species produce showy“flowers”through modifications of leaves(br...Compared with most flowers where the showy part comprises specialized leaves(petals)directly subtending the reproductive structures,most Zingiberaceae species produce showy“flowers”through modifications of leaves(bracts)subtending the true flowers throughout an inflorescence.Curcuma alismatifolia,belonging to the Zingiberaceae family,a plant species originating from Southeast Asia,has become increasingly popular in the flower market worldwide because of its varied and esthetically pleasing bracts produced in different cultivars.Here,we present the chromosome-scale genome assembly of C.alismatifolia“Chiang Mai Pink”and explore the underlying mechanisms of bract pigmentation.Comparative genomic analysis revealed C.alismatifolia contains a residual signal of whole-genome duplication.Duplicated genes,including pigment-related genes,exhibit functional and structural differentiation resulting in diverse bract colors among C.alismatifolia cultivars.In addition,we identified the key genes that produce different colored bracts in C.alismatifolia,such as F3′5'H,DFR,ANS and several transcription factors for anthocyanin synthesis,as well as chlH and CAO in the chlorophyll synthesis pathway by conducting transcriptomic analysis,bulked segregant analysis using both DNA and RNA data,and population genomic analysis.This work provides data for understanding the mechanism of bract pigmentation and will accelerate breeding in developing novel cultivars with richly colored bracts in C.alismatifolia and related species.It is also important to understand the variation in the evolution of the Zingiberaceae family.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51775061,51575061)Chongqing Municipal Research Program of Frontier and Application Foundation of China(Grant No.cstc2018jcyj AX0087)
文摘The current research of wind turbine drivetrain is mainly concentrated in dynamic characteristics of gearbox with a specific suspension of main shaft, such as one-point and two-point suspension. However, little attention is paid to the e ects of these suspension configurations on the dynamic responses of wind turbine gearbox. This paper investigates the influences of suspension configurations of main shaft on the dynamic characteristics of drivetrain. For evaluating the dynamic behaviors of drivetrain with multi-stage transmission system more realistically, a dynamic modeling approach of drivetrain is proposed based on Timoshenko beam theory and Lagrange's equation. Considering the flexibility and di erent suspension configurations of main shaft, time-varying mesh sti ness excitation, time-varying transmission error excitation and gravity excitation, etc., a three-dimensional dynamic model of drivetrain is developed, and the dynamic responses of drivetrain are investigated. Results show that with the one-point suspension of main shaft, the resonance frequencies in gearbox, especially at the low-speed stage, obviously shift to the higher frequency range compared to the gearbox without main shaft, but this trend could be inversed by increasing main shaft length. Meanwhile, the loads in main shaft, main shaft bearing and carrier bearing are greatly sensitive to the main shaft length. Hence, the load sharing is further disrupted by main shaft, but this e ect could be alleviated by larger load torque. Comparing to the one-point suspension of main shaft, there occurs the obvious load reduction at the low-speed stage with two-point suspension of main shaft. However, those advantages greatly depend on the distance between two main bearings, and come at the expense of increased load in upwind main shaft unit and the corresponding main bearing. Finally, a wind field test is conducted to verify the proposed drivetrain model. This study develops a numerical model of drivetrain which is able to evaluate the e ects of di erent suspension configurations of main shaft on gearbox.
基金supported by the opening project of Laboratory of Ecology and Evolutionary Biology from Yunnan University and Shenzhen Zhongnonghuadu Ecological Technology Co.,Ltd.(R20012)to Z.W.,and the USDA National Institute of Food and Agriculture Hatch project 02685 to W.L.We gratefully acknowledge Daniel B Sloan(Colorado State University)and the personnel of the Wu laboratory for help with providing suggestions and revising the manuscript.
文摘Compared with most flowers where the showy part comprises specialized leaves(petals)directly subtending the reproductive structures,most Zingiberaceae species produce showy“flowers”through modifications of leaves(bracts)subtending the true flowers throughout an inflorescence.Curcuma alismatifolia,belonging to the Zingiberaceae family,a plant species originating from Southeast Asia,has become increasingly popular in the flower market worldwide because of its varied and esthetically pleasing bracts produced in different cultivars.Here,we present the chromosome-scale genome assembly of C.alismatifolia“Chiang Mai Pink”and explore the underlying mechanisms of bract pigmentation.Comparative genomic analysis revealed C.alismatifolia contains a residual signal of whole-genome duplication.Duplicated genes,including pigment-related genes,exhibit functional and structural differentiation resulting in diverse bract colors among C.alismatifolia cultivars.In addition,we identified the key genes that produce different colored bracts in C.alismatifolia,such as F3′5'H,DFR,ANS and several transcription factors for anthocyanin synthesis,as well as chlH and CAO in the chlorophyll synthesis pathway by conducting transcriptomic analysis,bulked segregant analysis using both DNA and RNA data,and population genomic analysis.This work provides data for understanding the mechanism of bract pigmentation and will accelerate breeding in developing novel cultivars with richly colored bracts in C.alismatifolia and related species.It is also important to understand the variation in the evolution of the Zingiberaceae family.
