Computational approach to the experimental determination of diffusion coefficients for oxygen and nitrogen in hydraulic fluids using the pressure-decay method
Computational approach to the experimental determination of diffusion coefficients for oxygen and nitrogen in hydraulic fluids using the pressure-decay method
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DOI：
10.25368/2020.36
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发表时间：
2020-06
期刊：
影响因子：
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通讯作者：
Andris Rambaks;Filipp Kratschun;Carsten Flake;Maren Messirek;K. Schmitz;H. Murrenhoff
中科院分区：
文献类型：
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作者：
Andris Rambaks;Filipp Kratschun;Carsten Flake;Maren Messirek;K. Schmitz;H. Murrenhoff
本文分析了压力衰减法测定液压油中气体扩散系数的适用性。首先，详细描述该方法并与其他测量方法进行比较。其次，对该体系的热力学和传质过程进行了研究。这导致四种不同的气相热力学模型与两种扩散模型相结合。第三，通过检查空气在水中的扩散过程，所有系统参数可从文献中获得的模型上的压力衰减方法的影响进行评估计算。结果表明，普通的压力衰减方法不适用于气体混合物，如空气，因此，一个新的方法来计算扩散系数的建议。
In the presented paper, the applicability of pressure-decay methods to determine the diffusivities of gases in hydraulic fluids is analysed. First, the method is described in detail and compared to other measurement methods. Secondly, the thermodynamics and the mass transfer process of the system are studied. This results in four different thermodynamic models of the gaseous phase in combination with two diffusion models. Thirdly, the influence of the models on the pressure-decay method is evaluated computationally by examining the diffusion process of air in water as all system parameters are available from literature. It is shown that ordinary pressure-decay methods are not applicable to gas mixtures like air and therefore a new method for calculating the diffusivities is suggested.