Jinwu Xiang, Kai Liu, Daochun Li, Chunxiao Cheng and Enlai Sha
The purpose of this paper is to investigate the unsteady aerodynamic characteristics in the deflection process of a morphing wing with flexible trailing edge, which is based on…
Abstract
Purpose
The purpose of this paper is to investigate the unsteady aerodynamic characteristics in the deflection process of a morphing wing with flexible trailing edge, which is based on time-accurate solutions. The dynamic effect of deflection process on the aerodynamics of morphing wing was studied.
Design/methodology/approach
The computational fluid dynamic method and dynamic mesh combined with user-defined functions were used to simulate the continuous morphing of the flexible trailing edge. The steady aerodynamic characteristics of the morphing deflection and the conventional deflection were studied first. Then, the unsteady aerodynamic characteristics of the morphing wing were investigated as the trailing edge deflects at different rates.
Findings
The numerical results show that the transient lift coefficient in the deflection process is higher than that of the static case one in large angle of attack. The larger the deflection frequency is, the higher the transient lift coefficient will become. However, the situations are contrary in a small angle of attack. The periodic morphing of the trailing edge with small amplitude and high frequency can increase the lift coefficient after the stall angle.
Practical implications
The investigation can afford accurate aerodynamic information for the design of aircraft with the morphing wing technology, which has significant advantages in aerodynamic efficiency and control performance.
Originality/value
The dynamic effects of the deflection process of the morphing trailing edge on aerodynamics were studied. Furthermore, time-accurate solutions can fully explore the unsteady aerodynamics and pressure distribution of the morphing wing.
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Zi Kan, Daochun Li, Shiwei Zhao, Jinwu Xiang and Enlai Sha
This paper aims to assess the aeroacoustic and aerodynamic performance of a morphing airfoil with a flexible trailing edge (FTE). The objective is to make a comparison of the…
Abstract
Purpose
This paper aims to assess the aeroacoustic and aerodynamic performance of a morphing airfoil with a flexible trailing edge (FTE). The objective is to make a comparison of the aerodynamic noise characteristics between the conventional airfoil with a flap and morphing airfoil and analyse the noise reduction mechanisms of the morphing airfoil.
Design/methodology/approach
The computational fluid dynamic method was used to calculate the aerodynamic coefficients of morphing airfoil and the Ffowcs-Williams and Hawking’s acoustic analogy methods were performed to predict the far-field noise of different airfoils.
Findings
Results show that compared with the conventional airfoil, the morphing airfoil can generate higher lift and lower noise, but a greater drag. Additionally, the noise caused by the one-unit lift of the morphing airfoil is significantly lower than that of the conventional airfoil. For the morphing airfoil, the shedding vortex in the trailing edge was the main noise resource. As the angle of attack (AoA) increases, the overall sound pressure level of the morphing airfoil increases significantly. With the increase of the trailing edge deflection angle, the amplitude and the period of sound pressure of the morning airfoil fluctuation increase.
Practical implications
Presented results could be very useful during designing the morphing airfoil with FTE, which has significant advantages in aerodynamic efficiency and aeroacoustic performance.
Originality/value
This paper presents the aerodynamic and aeroacoustic characteristics of the morphing airfoil. The effect of trailing edge deflection angle and AoA on morphing airfoil was investigated. In the future, using a morphing airfoil instead of a traditional flap can reduce the aircraft`s fuel consumption and noise pollution.
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Isabella Maria Weber and Gregor Semieniuk
American radical economists in the 1960s perceived China under Maoism as an important experiment in creating a new society, aspects of which they hoped could serve as a model for…
Abstract
American radical economists in the 1960s perceived China under Maoism as an important experiment in creating a new society, aspects of which they hoped could serve as a model for the developing world. But the knowledge of “actually existing Maoism” was very limited due to the mutual isolation between China and the US. This chapter analyses the First Friendship Delegation of American Radical Political Economists (FFDARPE) to the People’s Republic of China in 1972, consisting mainly of Union for Radical Political Economics (URPE) members, which was the first visit of a group of American economists to China since 1949. Based on interviews with trip participants as well as archival and published material, this chapter studies what we can learn about the engagement with Maoism by American radical economists from their dialogues with Chinese hosts, from their on-the-ground observations, and their reflection upon return. We show how the visitors’ own ideas conflicted and intersected with their perception of the Maoist practice on gender relations, workers’ management, and life in the communes. We also shed light on the diverging conceptions of the role for economic expertise between URPE and late Maoism. As the first in-depth study on the FFDARPE, we provide rich empirical insights into an ice-breaking event in the larger process of normalization in the Sino-US relations, which ultimately led to the disillusionment of the Left with China.
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This writing examines the remarkable career of the founding East Asian scholar at Montreal's Concordia University. He was the individual who did more than merely a college…
Abstract
Purpose
This writing examines the remarkable career of the founding East Asian scholar at Montreal's Concordia University. He was the individual who did more than merely a college professor after 37 years there. He had helped to shape a new course in Sino-Canadian relations.
Design
This paper will look at an element of soft power engagement between Canada and China before Deng Xiaoping's Open Door Policy. It also examines Concordia's achievement in establishing a China foothold in the early-1980s.
Findings
Canada has always been a pioneer in engaging Red China. Despite not having formal diplomatic ties until October 1970, Ottawa never abandoned its wish to seek a friendship with Beijing. Amidst the thawing China–Canada relations since 1970, Concordia University recruited a 25-year-old graduate student named Martin Singer to inaugurate its East Asian courses. Singer's auspicious academic career not only gave him to organize Canada's first and the largest student delegation to China but also enabled him to pioneer the first joint-postgraduate studies program between a Chinese and a Western postsecondary institution. He was also a key player in establishing a novel and unique relationship between the PRC and the Western world.
Originality
This paper provides a glimpse into China's early experience in engaging the world as it left behind decades of communist isolation. It also highlights how serendipities allowed people and institutions to advance in the wake of this exciting period in modern Chinese history.