Multi Scale Simulation Model for Temparature Prediction of Radial Lip Seals

用于径向唇形密封件温度预测的多尺度仿真模型

• 批准号: 245173332
• 负责人: Professor Dr.-Ing. Werner Haas
• 金额: --
• 依托单位: Institut für Maschinenelemente (IMA)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/245173332?language=en
• 关键词: Multi; Scale; Simulation; Model; Temparature

Elastomeric radial lip seals are used to seal rotating shafts. During operation frictional heat is generated in the contact area between the radial lip seal and the shaft. The more frictional heat is generated and the poorer this heat is dissipated, the hotter the contact area gets. High temperatures are extremely harmful to the sealing system. They significantly accelerate the aging of the lip seal elastomer and the lubricant and cause faster failures of the sealing system.To provide the required reliability of the sealing system, the temperatures must stay in the allowed range during operation. Therefore designers have to be able to estimate the temperature in the sealing contact already in the development stage. Today the estimation is mostly based on experience and expertise.Considerable errors occur due to the multitude and the mutual interactions of the influencing factors on the generation and dissipation of the frictional heat. The consequences of those estimation errors are overdimensioned (this means uneconomic) sealing systems or massive failures.Therefore in this research project a simulation model is developed for simulating the production and dissipation of the frictional heat. With this simulation model the temperature distribution in the sealing system and its periphery can be calculated.A multi scale concept is used for the simulation model to solve the effects running on different length scales efficiently. The simulation model describes the production of the frictional heat on the micro scale and the dissipation of the frictional heat on the macro scale. A Fortran program is developed as micro model, which describes the fluid flow in the hydrodynamic sealing gap using the Reynolds equation. The simulation model uses real surface topographies of the radial lip seal and the shaft. An existing conjugate heat transfer model is used as macro model. This simulation model allows a combined fluid flow and heat simulation. The heat transfer is not only calculated for the fluid domains but also for the solid domains of the sealing system.To resolve the interaction of heat generation and heat dissipation, the macro and the micro model are coupled and are solved iteratively. The whole simulation model and its components are validated and optimized by comparing the simulation results with extensive test runs on a multi-purpose test rig.A parameter study is performed with the validated simulation model to identify the influencing coefficients and their interactions on the temperature in the contact area. Based on the results of the parameter study and the validation experiments, an approximation method is developed for predicting the contact temperature during the development stage.

弹性径向唇密封用于密封旋转轴。在运行过程中，在径向唇密封和轴之间的接触区域产生摩擦热。产生的摩擦热越多，散热越差，接触区域就越热。高温对密封系统危害极大。它们显著地加速了唇密封弹性体和润滑剂的老化，并导致密封系统更快地失效。为了提供密封系统所需的可靠性，在操作过程中温度必须保持在允许的范围内。因此，设计人员必须能够在开发阶段估计密封接触的温度。今天的评估主要是基于经验和专业知识。由于影响摩擦热产生和耗散的因素众多且相互作用，会产生相当大的误差。这些估计误差的后果是过度（这意味着不经济）密封系统或大规模故障。因此，在本研究项目中，建立了一个模拟摩擦热产生和消散的仿真模型。利用该仿真模型可以计算出密封系统及其外围的温度分布。仿真模型采用多尺度概念，有效地解决了在不同长度尺度上运行的影响。该模拟模型描述了摩擦热在微观尺度上的产生和摩擦热在宏观尺度上的消散。开发了一个Fortran程序作为微观模型，用Reynolds方程描述流体在动压密封间隙内的流动。仿真模型采用径向唇密封和轴的真实表面形貌。宏观模型采用已有的共轭传热模型。该模拟模型允许结合流体流动和热模拟。不仅计算了密封系统的流体传热，还计算了密封系统的固体传热。为了解决产生热量和散热的相互作用，将宏观和微观模型耦合并迭代求解。通过将仿真结果与多用途试验台的大量试验结果进行比较，对整个仿真模型及其组成部分进行了验证和优化。利用验证后的仿真模型进行了参数研究，确定了接触区温度的影响系数及其相互作用。在参数研究结果和验证实验的基础上，提出了一种预测开发阶段接触温度的近似方法。