Development of fire pump impeller hydraulic CAD system

1 Introduction

Fire pump is the core component of the impeller, impeller design is related to the overall performance and service life of the machine. However, impeller hydraulic design requires a large number of complex calculations, comparison and repeated modifications, heavy workload, long design cycle. Therefore, the active development of hydraulic CAD (Computer Aided Design) system suitable for fire pump can not only reduce the design workload and improve the development speed and quality, but also have important theoretical significance and practical application value for the design of fire pump impeller.

2, development tools to choose

At present, in the CAD software market, there are many CAD software products available for CAD system support environment and development environment and tools [1], I-DEAS, Pro / E, UG and other high-end; , MDT, etc .; low-level AutoCAD. Among them, Autodesk introduced AutoCAD can be regarded as one of the most successful and most influential computer-aided design software. It has reasonable price, easy to use, open architecture, good versatility and other advantages, welcomed by the majority of engineering and technical personnel at home and abroad have been widely used. AutoCAD has now reached the initial version of AutoCAD 2004, the second development tools are constantly updated and increased, giving users more freedom of choice, so how to choose the right development tool has become a problem to be solved.

Due to the development of science and technology and the improvement of software development, fewer and fewer users are using Auto LISP and ADS development tools. Currently, ARX, VB, VBA and Visual LISP are the four development tools Comparison of development tools in Table 1).

Table 1 Comparison of four development tools

Among the above four development tools, ARX is based on the Visual C ++ platform. Like VB and VBA, ARX comes with a large amount of visual programming controls, so that the design of human-machine interface is more convenient and quick in software development , Which makes the software developed more personal, and Visual LISP seems to be lacking in this regard. Especially in the software development if you need to interface with the database, ARX, VB and VBA tools have a dedicated database control can be used directly, you can save a lot of tedious work.

Although ARX is powerful and fast, it is complex and difficult to understand. If the program fails to properly handle one of the details in Windows programming, the application, the development environment, and the entire Windows may be paralyzed. VB / VBA, though running at a relatively slow speed, has a simple syntax and provides a powerful graphical user interface. Many graphics algorithms are very efficient and work well even in slower languages ​​like VB / VBA. And, in most cases, VB / VBA is fast enough.

From the language structure, VBA [2] is a subset of VB, and their syntax structure is the same, the obvious difference is that all the features of VBA, like VB, but not as good as VB. The real difference is that VB is an independent development tool, it does not need to rely on any other application, it has its own completely independent working environment and compile, connect the system. VBA is not the case, it does not have its own independent working environment, it must be attached to a main application, such as Office, AutoCAD, left the main application VBA will no longer exist, which limits its application in the development, but also the author VBA did not choose the main reason. Therefore, the choice of Visual Basic 6.0 for fire pump hydraulic CAD software development, make full use of VB itself functions, to improve the AutoCAD in addition to the graphics outside the relatively weak links, in order to achieve complementary advantages between the program.

3, the system interface and operating requirements

3.1, the system operation requirements To make the system to run well on the computer, the computer system should have the following hardware and software configuration:

3.1.1, hardware configuration

(1) Pentium 133 above CPU;
(2) Above 32MB basic memory (64MB or above is recommended);
(3) shows more than 16-bit enhanced color;
(4) 300MB hard disk space.

3.1.2, software configuration

(1) Windows9X or WindowsNT4.0 and above operating system;
(2) AutoCAD2000 or above;
(3) Access97 or above.

3.2, System Interface As shown in Figure 1, the system interface consists of the title bar, menu bar, toolbar, software operating area and status bar.

4, the system design features and design techniques

4.1, design features

(1) friendly user interface, easy to operate. Mode of operation Man-machine dialogue mode throughout the design process throughout the interactive design ideas, the use of dialog boxes and menus to convey and process information, so that designers can better grasp the design process.
(2) large amount of data, the relationship is complex. In the process of hydraulic design, there are many parameters involved, and subsequent designs often use the previous design data. For example, the basic parameters of the impeller should be used to draw the axial projection diagram. Projection of the specific data and so on.
(3) a lot of graphics information processing. In real-time operation, there are a lot of graphics to deal with. Both the intermediate bitmap (.bmp) save, and finally the AutoCAD graphics (.dwg) output.
(4) programming to fully take into account the different habits of users, providing multiple operating tips and guides: Tips can help users reduce operational errors; operation wizard allows users to make their own way. Help users to expand their own files, the system has good maintainability. In considering the professional at the same time, try to improve the versatility and practicality of the program.

4.2, Design Technology

4.2.1 Interactive Technology It should be pointed out that: CAD is not completely design automation, CAD will give top priority to people's dominance and creativity while giving full play to the strengths of computers and bringing them together. Therefore, in order to give designers the space to play design experience, the system adopts some human-computer interaction to establish a channel for the exchange of man-machine information in the form of dialog boxes and menus.

1 Introduction

Fire pump is the core component of the impeller, impeller design is related to the overall performance and service life of the machine. However, impeller hydraulic design requires a large number of complex calculations, comparison and repeated modifications, heavy workload, long design cycle. Therefore, the active development of hydraulic CAD (Computer Aided Design) system suitable for fire pump can not only reduce the design workload and improve the development speed and quality, but also have important theoretical significance and practical application value for the design of fire pump impeller.

2, development tools to choose

At present, in the CAD software market, there are many CAD software products available for CAD system support environment and development environment and tools [1], I-DEAS, Pro / E, UG and other high-end; , MDT, etc .; low-level AutoCAD. Among them, Autodesk introduced AutoCAD can be regarded as one of the most successful and most influential computer-aided design software. It has reasonable price, easy to use, open architecture, good versatility and other advantages, welcomed by the majority of engineering and technical personnel at home and abroad have been widely used. AutoCAD has now reached the initial version of AutoCAD 2004, the second development tools are constantly updated and increased, giving users more freedom of choice, so how to choose the right development tool has become a problem to be solved.

Due to the development of science and technology and the improvement of software development, fewer and fewer users are using Auto LISP and ADS development tools. Currently, ARX, VB, VBA and Visual LISP are the four development tools Comparison of development tools in Table 1).

Table 1 Comparison of four development tools

Among the above four development tools, ARX is based on the Visual C ++ platform. Like VB and VBA, ARX comes with a large amount of visual programming controls, so that the design of human-machine interface is more convenient and quick in software development , Which makes the software developed more personal, and Visual LISP seems to be lacking in this regard. Especially in the software development if you need to interface with the database, ARX, VB and VBA tools have a dedicated database control can be used directly, you can save a lot of tedious work.

Although ARX is powerful and fast, it is complex and difficult to understand. If the program fails to properly handle one of the details in Windows programming, the application, the development environment, and the entire Windows may be paralyzed. VB / VBA, though running at a relatively slow speed, has a simple syntax and provides a powerful graphical user interface. Many graphics algorithms are very efficient and work well even in slower languages ​​like VB / VBA. And, in most cases, VB / VBA is fast enough.

From the language structure, VBA [2] is a subset of VB, and their syntax structure is the same, the obvious difference is that all the features of VBA, like VB, but not as good as VB. The real difference is that VB is an independent development tool, it does not need to rely on any other application, it has its own completely independent working environment and compile, connect the system. VBA is not the case, it does not have its own independent working environment, it must be attached to a main application, such as Office, AutoCAD, left the main application VBA will no longer exist, which limits its application in the development, but also the author VBA did not choose the main reason. Therefore, the choice of Visual Basic 6.0 for fire pump hydraulic CAD software development, make full use of VB itself functions, to improve the AutoCAD in addition to the graphics outside the relatively weak links, in order to achieve complementary advantages between the program.

3, the system interface and operating requirements

3.1, the system operation requirements To make the system to run well on the computer, the computer system should have the following hardware and software configuration:

3.1.1, hardware configuration

(1) Pentium 133 above CPU;
(2) Above 32MB basic memory (64MB or above is recommended);
(3) shows more than 16-bit enhanced color;
(4) 300MB hard disk space.

3.1.2, software configuration

(1) Windows9X or WindowsNT4.0 and above operating system;
(2) AutoCAD2000 or above;
(3) Access97 or above.

3.2, System Interface As shown in Figure 1, the system interface consists of the title bar, menu bar, toolbar, software operating area and status bar.

Figure 1 system interface

4, the system design features and design techniques

4.1, design features

(1) friendly user interface, easy to operate. Mode of operation Man-machine dialogue mode throughout the design process throughout the interactive design ideas, the use of dialog boxes and menus to convey and process information, so that designers can better grasp the design process.
(2) large amount of data, the relationship is complex. In the process of hydraulic design, there are many parameters involved, and subsequent designs often use the previous design data. For example, the basic parameters of the impeller should be used to draw the axial projection diagram. Projection of the specific data and so on.
(3) a lot of graphics information processing. In real-time operation, there are a lot of graphics to deal with. Both the intermediate bitmap (.bmp) save, and finally the AutoCAD graphics (.dwg) output.
(4) programming to fully take into account the different habits of users, providing multiple operating tips and guides: Tips can help users reduce operational errors; operation wizard allows users to make their own way. Help users to expand their own files, the system has good maintainability. In considering the professional at the same time, try to improve the versatility and practicality of the program.

4.2, Design Technology

4.2.1 Interactive Technology It should be pointed out that: CAD is not completely design automation, CAD will give top priority to people's dominance and creativity while giving full play to the strengths of computers and bringing them together. Therefore, in order to give designers the space to play design experience, the system adopts some human-computer interaction to establish a channel for the exchange of man-machine information in the form of dialog boxes and menus.

4.2.2 Modular Technology Modular technology is a commonly used method of designing CAD systems. The system is divided into various functional modules, and then divided into modules to design, and finally the synthesis of a system, which is conducive to system development, commissioning and maintenance, but also conducive to system updates.

4.2.3 ActiveX Automation Interface Technology ActiveX Automation provides a programming interface that allows users to easily customize AutoCAD using a variety of ActiveX client programming languages ​​such as VB, Delphi, and more. It can be used for applications in Windows operating on AutoCAD objects such as creating views in AntoCAD, specifying and extracting extended data, exporting graphics to peripherals, adding specialized objects to AutoCAD, and more. Using VB, Delphi and other programming languages, you can achieve the seamless connection of applications on the Windows platform, so that all programs can be integrated in a unified operating environment.

4.2.4, Database Technology Database [3] Mainly store design calculations, drawings and various types of standard data. The purpose of establishing such a database is to reduce or even eliminate the need to manually access design data in computer-aided design. At the same time, the intermediate data in the design is stored in the database to reduce the number of data output and input.

5, functional module division and flow chart

5.1, hydraulic design module function module division Fire pump CAD system hydraulic design module consists of four sub-modules:

(1) basic parameters to determine the module: including the basic parameters of the pump to determine and determine the basic parameters of the impeller;
(2) axial flow channel design module;
(3) leaf type drawing module;
(4) wood model drawing module.

The relationship between the various modules shown in Figure 2.

Figure 2 hydraulic design of functional modules

5.2, hydraulic design flow chart

Impeller hydraulic design flow chart shown in Figure 3.

6, concluding remarks

Fire pump hydraulic CAD system development has great practical significance, to achieve the calculation and drawing accurate, short design cycle, simple and intuitive effect, to achieve the desired purpose. Based on the flow field analysis and performance prediction of mature CFD software, the hydraulic design method is further improved and corrected, which is one of the focuses and directions of future research.