西北工业大学学报最新文献_第10页

A large-deflection deformation reconstruction method for semi-flexible plate nozzle based on strain-moment relationship 基于应变矩关系的半柔性板喷管大挠度变形重建方法

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061312

C. Yu, Zhili Zhang, Xuqing Nie, Long Zhang

{"title":"A large-deflection deformation reconstruction method for semi-flexible plate nozzle based on strain-moment relationship","authors":"C. Yu, Zhili Zhang, Xuqing Nie, Long Zhang","doi":"10.1051/jnwpu/20224061312","DOIUrl":"https://doi.org/10.1051/jnwpu/20224061312","url":null,"abstract":"To enhance the health detection capability of the semi-flexible plate nozzle in a supersonic wind tunnel, a large-deflection deformation reconstruction algorithm for a semi-flexible plate nozzle based on the strain-moment relationship is developed. The multi-jack semi-flexible plate nozzle in the supersonic wind tunnel is studied; its mechanical model of contour assembly is established. The differential equation of flexible plate contour curve is deduced, and the elliptic integral expression of the flexible plate deformation is given. Based on the deformation theory of a rectangular thin plate, the deformation reconstruction algorithm is modified, and its correction effect is simulated and analysed with the finite element method. The maximum deviation after correction is only 10.78% compared with that before correction. The 0.3 m semi-flexible plate nozzle is used as the experimental platform to carry out the experimental study. The experimental results show that under the 6 Mach number, the large-deflection deformation reconstruction results based on strain-moment relationship are in good agreement with the experimental results. The coordinate deviation of the nozzle throat position is about 6.12% compared with the structural deformation, thus verifying that the deformation reconstruction algorithm in this paper is effective and accurate.","PeriodicalId":39691,"journal":{"name":"西北工业大学学报","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47584772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fault detection method of secondary sound source in ANC system based on impedance characteristics 基于阻抗特性的ANC系统二次声源故障检测方法

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061242

Haijian Dai, Kean Chen, Yang WANG, Haoxin Yu

引用次数: 1

WSN latency optimization based on path calculation method 基于路径计算方法的WSN时延优化

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061394

P. Zhu, J. Ren, Zhiyuan Ren

引用次数: 1

Lateral attitude control of solar-powered UAV with high aspect ratio 高纵横比太阳能无人机横向姿态控制

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061223

Bo Wang, Heng-wei Zhang, Z. Gao

引用次数: 2

Research on transition corridor boundary of distributed propulsion VTOL fixed wing 分布式推进垂直起降固定翼过渡通道边界研究

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061195

Yuxuan Cheng, Zhou Zhou, Kelei Wang

{"title":"Research on transition corridor boundary of distributed propulsion VTOL fixed wing","authors":"Yuxuan Cheng, Zhou Zhou, Kelei Wang","doi":"10.1051/jnwpu/20224061195","DOIUrl":"https://doi.org/10.1051/jnwpu/20224061195","url":null,"abstract":"The transition state is the most critical and dangerous state of the VTOL fixed wing aircraft in the whole flight process. In this paper, a transition corridor for a distributed propulsion VTOL fixed-wing aircraft is studied based on the lift characteristics of the wing and the power constraints of the power unit. Firstly, according to the sliding flow theory, the dynamic characteristics models of the lift fan system in the front part of the fuselage and the distributed duct system in the rear part of the fuselage were established by introducing the influence factor of the duct, and verified with the test data. Secondly, according to the lift characteristics of the wing, the transition curves of the aircraft at different angles of attack are calculated, in which the transition curves corresponding to the zero-lift attack angle and stall attack angle constitute the lift characteristics transition corridor of the distributed propulsion VTOL fixed-wing aircraft. Finally based on the dynamic performance of the power unit model, calculate the lift characteristic transition each state point in corridor corresponding power demand, according to the power limit of the lift fan system, distributed duct system and power unit total power limitation, get distributed to promote vertical take-off and landing a fixed wing aircraft power limitation in lifting features and power unit under the condition of complete transition corridor. The final results show that the minimum forward velocity is inversely proportional to the attack angle. The power required by the tail distributed duct system will exceed the limit when the aircraft is in low speed and small dip angle transition. For the power limit boundary required, the power limit condition of individual component is stricter than the total power limit condition. The research results of this paper can provide some reference for the transition corridor research of such VTOL fixed-wing aircraft, and on this basis, the subsequent work such as parameter sensitivity analysis and control system design of transition corridor can be carried out.","PeriodicalId":39691,"journal":{"name":"西北工业大学学报","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44814099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Infrared and visible image fusion algorithm based on split-attention residual networks 基于分散注意残差网络的红外与可见光图像融合算法

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061404

Kun Qian, T. Li, Zhe Li, Meishan Chen

引用次数: 0

A dense obstacle avoidance algorithm for UAVs based on safe flight corridor 基于安全飞行走廊的无人机密集避障算法

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061288

L. Fan, Haozhe Zhang, Zhao Xu, Mingwei Lyu, Jin-wen Hu, Chunhui Zhao, Xiaobin Liu

{"title":"A dense obstacle avoidance algorithm for UAVs based on safe flight corridor","authors":"L. Fan, Haozhe Zhang, Zhao Xu, Mingwei Lyu, Jin-wen Hu, Chunhui Zhao, Xiaobin Liu","doi":"10.1051/jnwpu/20224061288","DOIUrl":"https://doi.org/10.1051/jnwpu/20224061288","url":null,"abstract":"Aiming at the problem of autonomous obstacle avoidance of fixed-wing UAVs in a complex, dense and multi-obstacle environment, a path planning algorithm for fixed-wing UAVs based on a safe flight corridor is proposed. The difficulty of avoiding dense obstacles lies in the choice of obstacle circumvention and traversal: although circumvention is safer, the flight cost is greater; although the traversal cost is lower, the safety threat is higher. How to quickly solve the optimal path is the core issue. This paper firstly defines a safe flight corridor innovatively based on the maneuvering characteristics of fixed-wing UAVs and the Dubins curves. By comprehensively considering UAV flight safety and flight costs, an obstacle threat evaluation function is constructed. Secondly, in view of the computational complexity caused by the dense obstacles, an obstacle clustering algorithm based on obstacle density is proposed, and the nonlinear evaluation function in a high dynamic environment is quickly approximated by Monte Carlo sampling method. Finally, simulations verify the effectiveness of the proposed algorithm in solving dense obstacle avoidance for fixed-wing UAVs.","PeriodicalId":39691,"journal":{"name":"西北工业大学学报","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49249295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Image enhancement method based on exposure fusion for UAV aerial photography 基于曝光融合的无人机航拍图像增强方法

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061327

Liangliang Li, Jian-lin Ren, Peng Wang, Z. Lyu, Mengyu Sun, Xiaoyan Li, Wuqi Gao

引用次数: 0

Improved reduce-order modeling of bidirectional interleaved boost with coupled inductors converter 耦合电感变换器双向交错升压降阶模型的改进

西北工业大学学报 Pub Date : 2022-10-01 DOI: 10.1051/jnwpu/20224051046

Yuchen Zhang, Ruiqing Ma, P. Fan

引用次数: 1

Relationship of fracture behavior and stress triaxiality of additive manufactured Ti-6Al-4V 增材Ti-6Al-4V断裂行为与应力三轴性的关系

西北工业大学学报 Pub Date : 2022-10-01 DOI: 10.1051/jnwpu/20224050962

B. Gao, Wei Huang, Shen Wang, Shuangyin Zhang, Xianmin Chen

引用次数: 0