Study Of Structure Optimization And Viscosity Impact On Rotameter

Ratometer has such features as simple structure, low cost, convenient operation, stable operating characteristics and wildly application. Especially the metal tube rotameter is one of the most important flow meters in process control field. Many experts and scholars have been concerned on looking for an efficient way to optimize the transducer structure of rotameter in order to improve its performance and searching for the viscosity influence law of rotameter, etc. From the above two issues, this paper had been studied rotameter as well.This paper studied on designing and optimizing the transducer structure and geometric parameters of large diameter cone rotameter. Taking 200mm diameter and 100mm diameter short-tube rotameter as examples, the design thought was introduced in detail. The CFD method was used to compare and analyze the different structure of orifice rotameter. And a kind of dual-cone orifice rotameter designing with high linearity and low pressure loss was given. This paper proposed the method of determining the cone height of dual-cone float and the diameter of cone connection part, which was based on the ration between the linear turning point flow and maximum flow. The dual-cone structure optimal parameters of DN100 orifice rotameter were presented.Based on viscous fluid theory of the boundary layer and flow resistance, concerned the viscous friction force effect of the float, the impact factors of orifice rotamater volume flow were analyzed theoretically. The effect of the measured flow temperature on the metal tube rotameter performance was studied by combining theoretical analysis and CFD numerical calculation. The experiments of orifice rotameter on variable temperature oil calibration apparatus were done, the general viscosity formula and the analytical formula of DN25 orifice rotameter were given. CFD method was used to study the viscosity influence of orifice rotameter in micro-flow field perspective, the critical Reynolds number and viscosity model under different Reynolds numbers was proposed for CFD method.Based on the modularization idea, this paper designed a common database which has the entire jou file for modeling and calculation, and structure parameters of rotameter transducer. A highly readable and simple-operating rotameter common simulation platform was designed as well which can calculate the Reynolds number of upstream straight section automatically based on fluid properties and choose the proper viscosity model.These methods applied in optimizing the rotameter transducer structure and studying viscosity effect presented in this paper can be extended to the design and application of other type flow meter.