Application of the hottest CFDesign in pump indust

2022-08-18
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The application of CFDesign in the pump industry

I. Introduction to CFD application technology

cfd (Computational Fluid Dynamics) is designed to simulate the complex fluid motion laws involved in engineering problems by solving a set of basic equations describing fluid motion (Navier Stokes equations). CFD integrates computational mathematics, computer technology, physical models, CAD, visualization and other disciplines and becomes a marginal interdisciplinary subject. CFD originated in the 1970s. In just a few decades, CFD has been widely used in aerospace, energy, shipbuilding, automobile, chemical industry, oil and gas, heating and ventilation, electronics, polymer processing, food, biomedicine and other industries. At present, CFD commercial software has become a general basic tool and plays an important role in product development, design and fault diagnosis of large enterprises and R & D institutions around the world. CFD technology has become one of the most important core technologies in CAE. CFD was originally just a discipline that studied numerical formats and computational methods. After more than 30 years of efforts, CFD has been industrialized, and its research and development work has also developed into a complex system engineering, It mainly includes the following aspects:

1) mathematical models and numerical solutions (A. the ground line is not connected or poorly contacted; B. the electrical appliance is damp; C. the phase line conductor connector is in contact with the body numerics)

2) physical models

3) model validation

4) geometric modeling/cad integration

5) post processing/visualization (postprocessing/visualization)

6) computing turnaround

mathematical models, numerical solutions and physical models have always been the main content of CFD Research. In the 1950s, the mathematical theoretical foundation of the finite difference method of partial differential equations was basically laid. There are mainly the characteristic method and the famous stability criterion CFL condition proposed by courant, Friedrichs and Lewy, the numerical solution theory of nonlinear hyperbolic equations established by von Neumann, richtmyer and lax, and the stability theory of unsteady hyperbolic and hyperbolic parabolic partial differential equations established by lax and kresis. The establishment of these theories objectively created conditions for the prosperity of later research on computational formats and methods. In the mid-1960s, panel method appeared and was applied to aircraft design, marking the beginning of CFD application in industry

since the 1970s, CFD method has made major breakthroughs. On the one hand, it comprehensively solves the numerical calculation method of transonic potential flow, and on the other hand, it uses time-dependent method to solve compressible Euler equation and N-S equation to simulate complex flow field. Potential flow methods mainly include the type correlation method of Murmann and Cole, the improvement of Jameson's rotation scheme, and the implicit approximate factorization (AF) method proposed by balhaus, Lomax and Steger. Early time-dependent methods used to solve compressible Euler equations and N-S equations include MacCormack algorithm and AF method of beam and warming. Since the main governing equation solved by time-dependent method is a single hyperbolic equation, and the theoretical basis of its definite solution is perfect, this kind of method has been used to solve Euler equation and N-S equation to simulate transonic and supersonic flow fields for quite a long time later

since the late 1970s, the research on the computational formats and methods of numerically solving Euler equations and N-S equations has reached a higher level, and a considerable number of high-precision and high-resolution difference schemes have been developed, such as total variation reduction (TVD) scheme, essentially no oscillation (ENO) scheme, no fluctuation and no free parameter dissipation (NND) scheme, vector flux splitting scheme and flux difference splitting scheme. In addition, There is also the multi-step Runge Kutta finite volume method developed by Jameson et al. These schemes and methods can be used to simulate the non smooth flow field including shock wave, viscous interference, separated vortex and unsteady effect, which makes great progress in the numerical simulation of complex flow fields such as supersonic, hypersonic, transonic and low speed

the development of CFD has been affected by the hydraulic universal testing machine. Why can't the machine be widened? To the constraints of computer speed and capacity. The above achievements in numerical formats and methods after the 1970s are promoted by the development of computer technology. In order to meet the needs of large-scale and super large-scale computing, Cray-1 supercomputer appeared in the mid-1970s, Cray XMP and ibm3090 were launched in the 1980s, and Cray T3D and IBM SP2 were launched in the mid-1990s. In the late 1990s, the development of computers was even more rapid. IBM "deep blue" took the lead, but in one year, IBM launched blue gene, which is 1000 times faster than "deep blue". At present, IBM is producing ASCI white, an advanced strategic computer with a speed of 12 trillion 300 billion instructions per second. In line with the rapid improvement of computer performance, since the mid-1980s, large-scale parallel processing technology has become a hot spot in CFD Research, with remarkable achievements

lattice generation technology is another important development direction of CFD technology. Compared with the development of numerical format, calculation method and computer technology, the development of lattice generation technology lags behind. Taking the CFD numerical simulation of modern advanced fighter F-22 as an example, its geometric shape is very complex. In a CFD operation, lattice generation and related geometric modeling account for about 80% of the total work

however, the adaptability of structured lattices to complex geometric shapes is very poor, and the workload of CFD modeling and lattice generation is still large. Especially in the process of aircraft modification, although only partial modifications are made, it still needs to be re divided and generated into grids, which costs a lot of manpower and time. In view of this, unstructured lattice generation technology was vigorously developed in the 1990s

the combination of unstructured lattice technology and finite volume method (finite element) has promoted the industrialization of CFD. The 1990s is the high-speed mature period of CFD development. CFD technology has been widely used in the above fields. I hope you can understand these applications, which not only improves the design level, but also verifies and improves the CFD technology method, and finally promotes the rapid transformation of CFD technology into a practical, fast and powerful analysis and design tool, creating huge economic benefits

II. Application of CFDesign in the pump industry

at present, the competition in China's pump industry is very fierce. With the reform and opening up and China's entry into WTO, many multinational enterprises in various industries in the world are rapidly entering the Chinese market. In the pump industry, many world pump giants have set up sites in China, and the pump industry is bound to usher in large-scale industry integration and industrial restructuring The market has higher and higher requirements for manufacturers in the pump industry. While improving product quality, we should also try to shorten the supply period, especially for special products (customers have special needs), which inevitably requires pump manufacturers to accelerate the use of CAD, CAE, CFD technology to improve the whole design process. Therefore, the introduction of CFD technology has the following necessity for the pump industry

predictive pump design is a complex process, In the design, various factors affect each other, so that the pumps that meet the given requirements have different design schemes or results. Using CFD technology, the required design schemes can be selected from a large number of design schemes in the early design stage, thus greatly reducing the blindness in the design. In addition, CFD simulation is the only effective way to obtain data for products that work under many specific conditions

insight CFD provides a powerful tool for engineers to intuitively understand the complex flow phenomenon in the product, penetrate the tactile inside the product, and understand the physical essence. This is very important for engineers to improve their design ability to design new products, improve and optimize equipment

a lot of experience shows that the use of CFD technology greatly shortens the time to market, improves product performance, and reduces design and production costs

III. features of CFDesign software

cfdesign is a new generation CFD tool developed by brni (Blue Ridge numerics Inc.) in the United States. The design concept of the software is to integrate CFD into the mainstream of product design and become the mainstream CFD tool of product design, rather than the enigmatic "ivory tower" exclusive to a few CFD experts. CFDesign is directly embedded in the CAD design process, which enables engineers to quickly select schemes and greatly reduces the number of sample tests

since the release of CFDesign software in 1992, cf5 mining and Alibaba have been working together to build a trading platform with leading competitiveness in the industry. Design has been closely integrated with the product design process, saving a lot of cost and time for product design, and has become the preferred CFD tool for product design and development engineers

cfdesign technology platform can be represented by the following flow chart:

Figure 1: CFDesign cutting-edge CFD technology platform

the whole design platform includes the following links:

CAD connection

· directly use the core parts and assembly models of CAD system. These CAD systems include: pro/engineer, Solidworks, Autodesk Inventor, mechanical desktop, CATIA, UGS NX, Unigraphics, solid edge, I-DEAS, alibre, cocreate, ironcad, and other mainstream CAD systems

· maintain a combination relationship with CAD models, such as lattice size and operating conditions

· for geometric complexity, size, assembly There are no restrictions on the wall thickness

· automatic generation of fluid region

lattice generation

· the revolutionary use of finite element method to generate lattices ensures the rapid and accurate analysis of complex models Automatic lattice generation

· automatic monitoring and interpretation of small features

· automatic lattice generation in the fluid boundary layer

· easy to control the adjacent lattice size

simulation specification

· has the ability to solve various fluid problems encountered in the process of product development

· advanced, fast and robust solver

· can be integrated and coupled with other simulation environments: ABAQUS, ANSYS, cosmos, I-DEAS, mechanica, Nastran

calculation simulation

· can quickly solve complex problems on PC

· make full use of network computing resources

design evaluation

· interactive comparison of various design schemes under one window

· closely combined with the development of 3D product performance

engineers can quickly perform dozens of calculations from multiple schemes, Quickly find the best solution

generate the performance curve and efficiency curve of the pump

design communication

· provide interactive 3D document formats: Web pages, MS office applications, etc.

· the whole simulation process does not need mechanical CAD or CFD experience (end)

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