The influence of uniform flow orifice on the effect of Naturally stratified Chilled water-storage tank
The widely use of cooled storage technology in our country will be an irreversible trend with the development and improvement of the TOU price policy. Naturally stratified Chilled water-storage is a very important cool storage technology. In this paper, the effect of using uniform flow orifice in naturally stratified water-storage with slotted pipe diffuser is studied by contrast experiments firstly. Then the cases with uniform flow orifice are simulated. Through the comparison of experimental data and simulation data, the correctness of the mathematical model is verified. Finally, the effect of water-storage is studied by simulation when the uniform flow orifice is set with different voltage drop. Conclusions can be obtained as follows: the layered effect is greatly improved by setting the uniform flow orifice; it is when the voltage drop of uniform flow orifice is in an appropriate range which is about ten to tens Pa that the improvement is obvious.
Simulation Study of Naturally Stratified Chilled Water Storage Tank Diffuser
This paper introduces the study about the present naturally stratified chilled water storage,and analyses the factors affecting thermal performance of stratified tanks.Establishes a model of 3 different type diffusers with the CFD simulation software FLUNET 6.Simulates and analyses the distribution of temperature and the velocity field during the charging,and the design of the diffuser is optimized.
Numerical analysis and experimental observation of guidewire motion in a blood vessel model.
We have developed a computer-based system to simulate a guidewire in blood vessels for surgical planning, intra-operative assistance, and to facilitate the design of new guidewires. In this study, we compared simulation results with experimental results for validation of the simulation system. First, we inserted a commercial guidewire into a poly (vinyl alcohol) hydrogel blood vessel model using a two-axis automatic stage and measured the position of the guidewire tip and the contact force between the guidewire and the vessel. The experimental apparatus can be used not only for the validation of numerical analyses, but also as a simulation system. Second, similarly to the experiment, the motion of the guidewire in the blood vessel model was calculated when the proximal part of the guidewire model was pushed and twisted. The model of the guidewire is constructed with viscoelastic springs and segments, and the proximal part of the guidewire model is constrained by the fixed catheter model. Collisions between the guidewire and the vessel are calculated, and the contact forces are determined according to the stiffness of the vessel wall. The same tendency was seen in the trajectories and the contact force of both the experimental and simulated guidewire tips.