The Research And Development Of Flowmeter

Flowmeter is an important part of measurement science, and has been widely applied in production of industry and agriculture, national defence construction, scientific research work and civil economy. The research and development of flowmeter will be propitious to develop the product quality, improve efficiency of production and expedite the development of science and technology. Especially in the near future, we will face the crisis of energy, and the extent of automatization in industrial production will also get more and more. All these will make the status of flowmeter higher and higher in civil economy.In this thesis, the first part is to design a differential pressure(DP) flowmeter. Although there are many kinds of flowmeters on the market, they all have some deficiency and can not fully satisfy the requirement of science research and industrial application. The characteristic of DP flowmeter is cheap and simple structurally. But most of DP flowmeters bring large pressure loss, which can lead to jam and reduce their life. In order to find the higher precision, lower pressure loss and better repetition DP flowmeter, the groping work is included as follows:1. Designing a new kind of differential generator based on bernoulli equation. It has streamline structure, solve the problems of jamming and parting, and can be standardizationally produced. Besides, it can have high repetition and precision.2. Doing the experiment through different load orifice on the different position of velocity section in the pipeline. So the position of the best load orifice can be made certain.The second part is to invent a new flowmter. It must be able to measure the flux of vortical liquid in the pipeline with the large metrical range, but not be affected by upriver tubing. The emphasis of this part is to get velocity field and pressure field of vortical liquid with the experiment methods of LDV, hotwire and five-hole probe. The numerical simulation is also gotten. By the contrast of results with four deferent methods, the character of the swirler field can be known. In this part the flowing works are included: 1. Measuring the field of velocity and pressure in swirler by five-hole probe, hotwire and LDA. The tangent velocity is the main one of the three-dimensional velocity in the swirler, so it must be mainly measured. The axial velocity is related to backflow, so it can be measured as possible. The radial velocity is the least one, so it is very difficult to measure. To further design the flowmeter and the noncontact cupule, the pressure field, including static pressure and total pressure, is also very important.2. Simulating numerically the flow field of swirler of flowmeter with Fluent so as to enhance the reliability of experimental data.3. Designing the new kind of flowmeter on the whole.