Duo Q.,PLA Air Force Aviation University |
Jinfu F.,PLA Air Force Aviation University |
Jiaqiang Z.,PLA Air Force Aviation University |
Yongli L.,Engineering University
Engineering Review | Year: 2016
To analyze the air flow interference between upper and lower wings in axial ring wing configuration, NASA SC(2)-1006 supercritical airfoil is chosen as the basic airfoil. Flow field around the doublewing structure with different relative distances between upper and lower wings is numerically simulated, using SST k-ω turbulence model, and the numerical conclusion about the influence of relative distance D/L on the aerodynamic performance is drawn. It is shown that, at the speed Ma = 0.8, reflection of shockwave between the upper wing and the lower wing has a great negative effect on both lift and drag coefficient. When D/L = 0.1, and the angle of attack AOA = 0°, the resultant lift produced by the two wings is equivalent to that of the single wing, while the resultant drag is 4 times of that of the single wing, which shows a poor aerodynamic characteristic. With the increasing of the relative distance, the intensity of the shockwave between the upper and lower wings is weakened and the negative effect is relieved. Furthermore, the growth of the angle of attack AOA can obscure the negative effect. It could provide helpful reference to the design of axial ring wing aircraft..
Zhu Y.,Engineering University
2014 31th URSI General Assembly and Scientific Symposium, URSI GASS 2014 | Year: 2014
A novel compact eighth-mode substrate integrated waveguide (EMSIW) resonator is proposed. The dominant resonant mode of the proposed resonator is TE101 mode. Compared with the conventional SIW resonator, the size reduction of the resonator is up to more than 87.5%. By using source-load Cross coupling and magnetic coupling, a new filter with two EMSIW cavities is designed, which has four transmission zeros in the out-band. The measured results show good performance and agree well with the simulated results. © 2014 IEEE.
Yang P.,Engineering University
Proceedings - 2015 5th International Conference on Communication Systems and Network Technologies, CSNT 2015 | Year: 2015
The low-power wireless data acquisition and transmission system based on ZigBee is designed.The main work include the following aspects: 1)The circuit design and the software design of the system. 2)The multi-channel sensor data acquisition interface and the software of the system design. 3)Low-power design method for the node software. 4)The system based on ZigBee is build and debugged. The results show that the system has some advantages with lower data error rate. It is able to meet the needs of remote monitoring of the parameters on industrial environment. © 2015 IEEE.
Tian M.,Engineering University |
Li R.,PLA 61135 Unit
Proceedings - 2012 5th International Symposium on Computational Intelligence and Design, ISCID 2012 | Year: 2012
The class label of each feature vector in the dataset is respectively added in the corresponding feature vector as a feature value, which build a new vector called altered feature vector, all of which compose the altered dataset. It is demostrated that an SVM based on the altered dataset has advantages such as high generilization performance and little structure risk, compared with an SVM based on the original dataset. When predicting the unkown feature vector, different class labels (1 and -1) are respectively added to the unkown feature vector, and 2 altered feature vectors are got. Two hyperplane function values are obtained by substituting the 2 altered feature vectors into the hyperplane function respectively, and the symol (1 or -1) of the function value with larger absolute value is conducted as the class label of the unkown feature vector. Experiments results show that the proposed mehtod can enhance the recognition performance of an SVM effectively. © 2012 IEEE.
Bukhari I.A.,Engineering University |
Vollum R.L.,Imperial College London |
Ahmad S.,Engineering University |
Sagaseta J.,Imperial College London
Magazine of Concrete Research | Year: 2010
The current paper reviews existing design guidelines for strengthening beams in shear with carbon fibre reinforced polymer (CFRP) sheets and proposes a modification to Concrete Society Technical Report TR55. It goes on to present the results of an experimental programme which evaluated the contribution of CFRP sheets towards the shear strength of continuous reinforced concrete (RC) beams. A total of seven, two-span concrete continuous beams with rectangular cross-sections were tested. The control beam was not strengthened, and the remaining six were strengthened with different arrangements of CFRP sheets. The experimental results show that the shear strength of the beams was significantly increased by the CFRP sheet and that it is beneficial to orientate the FRP at 45° to the axis of the beam. The shear strength of FRP strengthened beams is usually calculated by adding individual components of shear resistance from the concrete, steel stirrups and FRP. The superposition method of design is replaced in Eurocode 2 by the variable angle truss model in which all the shear is assumed to be resisted by the truss mechanism. The current paper proposes a methodology for strengthening beams with FRP that is consistent with Eurocode 2. © 2010 Thomas Telford Ltd.