Multi physical field modeling of the hottest elect

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Multi physical field modeling of electric shaver

in the development history of electric shaver, the design and manufacture of the cutter cover has always required a high level of technology, which involves the intersection of multiple disciplines and the application of new processes and new technologies. Recently, the world's famous electric razor manufacturers have adopted new materials to manufacture the blade cover. Among them, Philips especially used COMSOL multiphysics to optimize the manufacturing process of its new generation of electric razor cover that will be market-oriented. According to ir Dr. redmer van tijum introduced that COMSOL multiphysics is a large-scale advanced numerical simulation software, which is widely used in scientific research and engineering calculation in various fields. It is called "the first real direct coupling analysis software of any multiple physical fields" by scientists in the world today. COMSOL multiphysics provides application modules specially designed for different fields, including acoustics, chemical engineering, geoscience, high-frequency electromagnetism, low-frequency electromagnetism, heat transfer, microsystem and structural mechanics

the first step in the manufacturing process of the cutter cover is to use transformation induced plastic steel. At this time, the thickness of the obtained cutter cover is too large, and the shape is not accurate enough, so further processing is required. For low-end electric shavers, Philips generally uses EDM to manufacture their blade covers. However, this method is not only expensive, but also requires uniform electrode distribution, so it can not be used to manufacture complex shape tool covers. The high-end electric shaver has three blades, and the corresponding blade cover also requires a more precise shape, and its manufacturing process is also more complex. Philips generally uses electrochemical machining to manufacture knife covers with complex shapes (Figure 1). This achievement will contribute to the development of portable small dialysis devices to make the blade fit more closely with the knife cover. Engineers need to have a more thorough understanding of the manufacturing process of the knife cover. Compared with doing experiments, using COMSOL multiphysics multi physical field function to simulate the whole manufacturing environment can save a lot of costs, and its optimization design function can also provide engineers with other important information

Figure 1: Philips launched a new generation of electric shaver. The three blade system requires a knife cover with very precise shape

electrochemical machining includes three parts, namely, an anode (knife cover) with controllable electrochemical decomposition, a preformed cathode (mold), and the fluid flow between the two. The metal on the surface of the knife cover is decomposed into metal ions by electrochemical reaction. Therefore, when the mold and voltage are determined, the overall dimension of the cutter cover can become very accurate under the action of electrochemical reaction

the electrolyte fluid between the knife cover and the mold contains not only metal ions, but also gases produced by the side effects of electrochemical reactions on the surface of the knife cover. The presence of gas will increase the Coulomb force of electrolyte on the cutter cover surface, which changes with the change of the shape of the cutter cover surface. This Coulomb force must be compensated immediately by adjusting the voltage. In addition, the law of conservation of matter and the basic properties of materials, such as the density in the fluid, must be considered in describing the electrochemical motion in the electrolyte

in the process of electrochemical machining, high-speed material exchange occurs on very thin materials, and the channel of electrolyte is also very narrow. Due to the reaction heat and resistance heat, the temperature will be very high, and even reach the boiling point when the electrolyte composition is inappropriate. While the cutter cover structure is constantly shaped over time, it is also subjected to the high pressure of electrolyte, which leads to the integrity of the cutter cover structure (3) the relative uncertainty u introduced by the indication error of the supporting weight of the lever requires a detailed understanding of functionalization and particle size and shape - when the particle is 2 (5) nm, 3; Great changes have taken place in sex, and there may be post elasticity. 2. Price: price is one of the major factors considered by the purchaser. High ambient temperature may also change fluid density. Therefore, the electrochemical machining process to be studied by Philips is a very complex multi physical field problem (Figure 2)

Figure 2: physical coupling variables that Philips must consider when simulating electrochemical machining (ECM), a multi physical field problem

multi physical field coupling analysis enables the machining process not only to guide the experimental method, but also to enable engineers to better understand the more essential physical connotation of machining means. Philips used COMSOL multiphysics to simulate the processing process. COMSOL multiphysics can process all relevant physical fields at the same time. In the process of numerical simulation, it can ensure that researchers have a clear understanding and understanding of the processing process

first investigate the electrical process. COMSOL multiphysics has a special module to deal with this problem. Engineers can add electrochemical application modes to these modules at will to simulate the reaction at the interface between the cutter cover and the electrolyte. The high openness of COMSOL

multiphysics enables engineers to define conductivity that changes with the location and heat of bubbles. In addition, the fluid mechanics module (non isothermal fluid) and the heat transfer module (convection and conduction) are directly coupled. In this process, the heat source term in the heat transfer equation depends on the current. In order to simulate the effect of temperature and gas pressure, a density description equation varying with temperature needs to be added to the density term of the fluid mechanics module

when simulating the machining process, the most important thing is to investigate the forming process of the cutter cover. Engineers first established the initial shape of the cutter cover in COMSOL multiphysics, and used a special ale mode (moving lattice) in the simulation process. According to the calculation results, the shape of the cutter cover can be easily and continuously updated, and it is coupled with the module that simulates the electrochemical reaction of phase transformation induced plastic steel decomposition. This simulation method is very suitable for describing the electrolyte channel and the fluid in it

Figure 3: the result data comes from the electric shaver

through the model shown in Figure 3, Philips applied COMSOL multiphysics to simulate the processing process of the new generation of electric shaver cover, so as to make the fit between the cover and the blade closer. In further research, COMSOL multiphysics will become a powerful tool for Philips to improve the production process and design new products. Two dimensional sectional view of the electrolyte channel between the cutter cover and the mold. Electrolyte flows in from the right side and out from the left side. The gas distribution (color) and flow field distribution (arrow) are shown in the figure. From the figure, it is easy to see the influence of fluid on gas distribution and the influence of gas intrusion into fluid on fluid acceleration. The bottom picture is the density distribution diagram of the fluid near the whole surface of the cutter cover. The location of the peak is the geometric bending of the cutter cover and the area where the metal decomposition is intense. (end)

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