Identification of oil-sludge interface using a numerical vibro acoustic approach

这个与INENCO合作的研究项目旨在开发一种工具，以确定在大型储油罐中积累的污泥剖面。目前，INENCO对确定大型储油罐中积累的污泥水平很感兴趣。在实际操作中，5到15英尺的污泥积聚在槽内，污泥水平在出口喷嘴附近较低，而在出口喷嘴对面的槽远端较高。储罐的高度通常在40到45英尺左右，由一个浮动的顶部组成，当降低时，将与储罐内不均匀分布的污泥接触，并可能增加屋顶损坏的风险，这是非常昂贵的。因此，作业通常保持在高原油水平，以避免浮顶故障。然而，这将导致存储容量的损失，从而导致生产的巨大损失。了解储罐内的污泥分布水平不仅可以最大限度地提高储罐内的存储容量，还可以降低生产成本，同时降低对浮顶的损坏风险。所提出的方法是基于振动声学，其中假设储罐中的波传播解对于特定的界面位置是唯一的，我们希望开发一种工具来提供这种表面位置。因此，将利用形状参数化来定义具有有限参数数量的唯一形状。随机生成的形状可以通过选择参数的随机值来产生。对于每个油和污泥界面层，几何结构将被网格化，然后对非均匀介质的波传播问题进行数值计算，该问题由频域亥姆霍兹方程建模。数值结果将得到包括油泥在内的区域内的近似压力波动。每个随机生成的形状的解将被简化为固定点的波属性与形状参数值之间的关系。将进行大量的模拟以生成一个神经网络，该网络给定几个点的波属性并输出定义形状的参数。

This research project in collaboration with INENCO is aiming at developing a tool to determine the sludge profile that is accumulated in large oil storage tanks. Currently, INENCO is interested in determining the sludge levels that are accumulated in large oil storage tanks. In practice, 5 to 15 feet of sludge is accumulated inside the tank where the sludge level is low near the outlet nozzle and much higher at the far end of the tank opposite the outlet nozzle. The tank height is typically around 40 to 45 feet and consists of a floating roof, which when lowered will have contact with the non-uniform distribution of the sludge inside the tank and can increase the risk of damage to the roofs which is very costly. Consequently, operation is usually kept at high crude oil levels to avoid floating roof failure. However, this will result in loss of storage capacity and thus, a big loss in production. Knowing the sludge profile levels inside the tanks will not only maximize the storage capacity inside the tanks, but also reduce the cost of production while at the same time, reducing the risk of damage to the floating roofs. The method proposed is based on vibro-acoustics, where by assuming that the wave propagation solution in a tank is unique to a specific interface location, we want to develop a tool that provides this surface location. Therefore, a shape parameterization will be utilized in order to define a unique shape with a limit number of parameters. Randomly generated shapes can be produced by selecting random values of the parameters. For each oil and sludge interface level, the geometry will be meshed and a numerical computation of the wave propagation problem modeled by the Helmholtz equation in the frequency domain for the heterogeneous media is then performed. The numerical results will yield the approximate pressure fluctuations in the domain which includes both the sludge and oil. The solution to each randomly generated shape will be simplified into a relation between the wave properties at a fixed point and the values of the shape parameters. A large set of simulation will be performed to generate a neural network that given the wave properties at a few points and outputs the parameters that define the shape.