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

与INENCO合作的这一研究项目旨在开发一种工具，以确定大型储油罐中积累的污泥分布。目前，INENCO有兴趣确定大型储油罐中积累的污泥水平。在实践中，5至15英尺的污泥积聚在罐内，其中污泥水平在出口喷嘴附近较低，而在罐的与出口喷嘴相对的远端处高得多。 罐的高度通常约为40至45英尺，并且由浮顶组成，浮顶在下降时将与罐内的污泥的不均匀分布接触，并且可能增加损坏浮顶的风险，这是非常昂贵的。 因此，操作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。 了解罐内的污泥剖面水平不仅可以最大限度地提高罐内的存储容量，还可以降低生产成本，同时降低浮顶损坏的风险。所提出的方法是基于振动声学，其中通过假设在坦克中的波传播解决方案是唯一的一个特定的接口位置，我们要开发一种工具，提供这个表面的位置。 因此，将利用形状参数化以限定具有有限数量的参数的唯一形状。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水平，几何形状将被网格化，然后在频域中的非均匀介质的亥姆霍兹方程建模的波传播问题的数值计算进行。数值计算结果将产生包括污泥和油的区域中的近似压力波动。每个随机生成的形状的解将被简化为固定点处的波的性质与形状参数的值之间的关系。将执行大量的模拟以生成神经网络，该神经网络在几个点处给出波的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.