In this paper, the bottom of the Dianshan Lake was selected as a test sample. The dynamic release of contaminated sediments into the overlying water column was experimentally investigated in an open water channel unde...In this paper, the bottom of the Dianshan Lake was selected as a test sample. The dynamic release of contaminated sediments into the overlying water column was experimentally investigated in an open water channel under different hydrodynamic conditions. The experimental results indicate that the Total Phosphorus （TP） release process can be divided into three stages： rapid release, slow release and equilibration release. In the initial release stage the measured TP concentration changes along the depth. The TP concentration near the sediment-water interface is higher than that near the water surface, but the TP concentration becomes uniform along the depth after 3 h. The dynamic release of re-suspension sediment pollutants is about 6 times higher than the static release of sediment-water interface. There are three main types of release mechanism： diffusion release, re-suspended pore water mixing release and re-suspended particles desorbing release.展开更多
In this paper, we propose a simulative experimental system in wind tunnel conditions lbr the separation of auxiliary fuel tanks from an aircraft. The experimental system consists of a simulative release mechanism, a s...In this paper, we propose a simulative experimental system in wind tunnel conditions lbr the separation of auxiliary fuel tanks from an aircraft. The experimental system consists of a simulative release mechanism, a scaled model and a pose measuring system. A new release mechanism was designed to ensure stability of the separation. Scaled models of the auxiliary fuel tank were designed and their moment of inertia was adjusted by installing counterweights inside the model. Pose param- eters of the scaled model were measured and calculated by a binocular vision system. Additionally, in order to achieve high brightness and high signal-to-noise ratio of the images in the dark enclosed wind tunnel, a new high-speed image acquisition method based on miniature self-emitting units was pre- sented. Accuracy of the pose measurement system and repeatability of the separation mechanism were verified in the laboratory. Results show that the position precision of the pose measurement system can reach 0.1 mm, the precision of the pitch and yaw angles is less than 0.1° and that of the roll angle can be up to 0.3°. Besides, repeatability errors of models＂ velocity and angular velocity controlled by the release mechanism remain small, satisfying the measurement requirements. Finally, experiments for the separation of auxiliary fuel tanks were conducted in the laboratory.展开更多
基金the National Natural Science Foundation of China (Grant Nos. 10972134, 11032007)the Shanghai Program for Innovative Research Team in Universities
文摘In this paper, the bottom of the Dianshan Lake was selected as a test sample. The dynamic release of contaminated sediments into the overlying water column was experimentally investigated in an open water channel under different hydrodynamic conditions. The experimental results indicate that the Total Phosphorus （TP） release process can be divided into three stages： rapid release, slow release and equilibration release. In the initial release stage the measured TP concentration changes along the depth. The TP concentration near the sediment-water interface is higher than that near the water surface, but the TP concentration becomes uniform along the depth after 3 h. The dynamic release of re-suspension sediment pollutants is about 6 times higher than the static release of sediment-water interface. There are three main types of release mechanism： diffusion release, re-suspended pore water mixing release and re-suspended particles desorbing release.
基金co-supported by the National Natural Science Foundation of China(Nos.51375075,51227004)the Special Funds of the National Natural Science Foundation of China(No.51227004)+2 种基金the National Basic Research Program of China(No.2014CB046504)the Fundamental Research Funds for the Central Universities of Chinathe Science Fund for Creative Research Groups of China(No.51321004)
文摘In this paper, we propose a simulative experimental system in wind tunnel conditions lbr the separation of auxiliary fuel tanks from an aircraft. The experimental system consists of a simulative release mechanism, a scaled model and a pose measuring system. A new release mechanism was designed to ensure stability of the separation. Scaled models of the auxiliary fuel tank were designed and their moment of inertia was adjusted by installing counterweights inside the model. Pose param- eters of the scaled model were measured and calculated by a binocular vision system. Additionally, in order to achieve high brightness and high signal-to-noise ratio of the images in the dark enclosed wind tunnel, a new high-speed image acquisition method based on miniature self-emitting units was pre- sented. Accuracy of the pose measurement system and repeatability of the separation mechanism were verified in the laboratory. Results show that the position precision of the pose measurement system can reach 0.1 mm, the precision of the pitch and yaw angles is less than 0.1° and that of the roll angle can be up to 0.3°. Besides, repeatability errors of models＂ velocity and angular velocity controlled by the release mechanism remain small, satisfying the measurement requirements. Finally, experiments for the separation of auxiliary fuel tanks were conducted in the laboratory.
