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Guo J.,Harbin Engineering University | Sun F.,China Special Vehicle Research Institute | Cao D.,Harbin Engineering University
Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University

The survivability of warships under multi-torpedo attack is much concerned by the designers and users. The maximum torpedo-attack resistance is analyzed based on the classic anti-sinking capability analysis. According to the flooding of damaged compartment under multi-weapon attacks, the relationship of the weapon accuracy and the warships' maximum anti-sinking capability, the connection between the survivability index and the weapon destruction radius, and the choice of limit sinking probability values are discussed. The sinking probability and the maximum hitting count of torpedoes to a warship under multi-weapon attacks can be obtained by the method. This method can also evaluate the warship anti-striking capability and the quality of the cabin layout plan, providing support for warship survivability design. Source

Zhu E.,Nankai University | Pang J.,Nankai University | Sun N.,China Special Vehicle Research Institute | Gao H.,Nankai University | And 2 more authors.
Nonlinear Dynamics

Aiming at flight property of airship, a trajectory tracking controller of airship horizontal model is designed based on active disturbance rejection control (ADRC). The six Degree of Freedom (DOF) dynamic model of airship is simplified at a horizontal plane. ADRC is used to realize the decoupling control for the multivariable system. The uncertain items of the model and external disturbances are estimated by the extended state observer (ESO) and dynamic feedback compensation is carried on at real time. The disturbance of wind is added to the simulation environment. The simulation results show that the designed tracking controller can overcome the influences of uncertain items of the model and external disturbances, and track the desired trajectory rapidly and steadily, and possess good robustness and control performances. © 2013 Springer Science+Business Media Dordrecht. Source

Qiu S.,Zhejiang University | Qiu S.,China Special Vehicle Research Institute | Wu L.,Zhejiang GongShang University | Zhang L.,Zhejiang University | And 2 more authors.
Huagong Xuebao/CIESC Journal

The effects of metaphenylene diamine (MPD) and trimesoyl chloride (TMC) concentration on the performance of reverse osmosis (RO) composite membranes were investigated. Different alcohols were added to the aqueous solution of MPD in order to improve the performance of as-prepared membranes. The maximal flux was found to be twice of the original flux. FTIR results suggest that the hydroxyl groups of alcohols reacted with TMC to form ester bonds and thus terminated the extension of polyamide molecular chains, and reduced the cross-linked degree of network structure, so that solute molecules are easy to penetrate through the membranes. The connection between membrane separation performance and solubility parameters of alcohols was investigated. When the solubility of alcohol is close to that of polyamide, the alcohol is easy to dissolve and penetrate in the nascent polyamide membrane, and therefore increases the reaction between the alcohol and TMC. The experiments exhibit that the addition of alcohols is an effective method for preparation of composite membrane with high flux. Under the optimum experimental conditions, the best mass fraction of additional alcohols in water phase is between 5% and 10% and as-prepared composite membranes exhibit high flux with a little sacrifice on rejection. © All Rights Reserved. Source

Wang M.,China Special Vehicle Research Institute | Wang M.,Key Aviation Scientific and Technological Laboratory of High Speed Hydrodynamic | Chu L.,Key Aviation Scientific and Technological Laboratory of High Speed Hydrodynamic | Chu L.,China Aviation Industry General Aircraft Co. | And 6 more authors.
Baozha Yu Chongji/Explosion and Shock Waves

The effect of hydrodynamic impact on the amphibious seaplane is an important consideration in its structural designing and intensity checking. In addition, such impact is a major factor affecting its structural weight. By varying two parameters: drop height and drop weight in the experiment, the pressure and the change of the free surface of liquid for three different wedges are dynamically measured. In the present work, the local pressure distribution, the impact pressure changing with time and the variety of the free surface on several free-falling wedges have been investigated. These wedges have been chosen from the representative cross section of amphibious seaplanes commonly used worldwide. By comparing the experimental results, the conclusion is reached that the wedge with a flared cross section reduces the impact pressure effectively when the amphibious seaplanes land on intricate waves. This study is expected to offer valuable reference for the hull designing of the amphibious seaplane. © 2016, Editorial Board of EXPLOSION AND SHOCK WAVES. All right reserved. Source

Zhu E.,Nankai University | Pang J.,Nankai University | Sun N.,China Special Vehicle Research Institute | Gao H.,Nankai University | And 2 more authors.
Chinese Control Conference, CCC

Airship is a kind of aerostat, which is lighter than air. The ascending lift is provided by buoyancy of low-density gas in the envelope. For the secure flight of airship, it is important to control the internal pressure to keep the pressure difference in a safe range. The traditional control rate can only make the pressure difference at a fixed value which relates to the initial states. The thought of fuzzy control is introduced to the traditional control rate. According to the error of pressure difference, the area of vent is changed. In the simulation environment, solar radiation and heat conduction are added on the basis of pressure control and atmosphere environment model. The results show that the pressure difference can track the set value well. © 2013 TCCT, CAA. Source

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