Wear ∎ (∎∎∎∎) ∎∎∎–∎∎∎
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A combined CFD/experimental methodology for erosion prediction A. Mansouri n, H. Arabnejad, S.A. Shirazi, B.S. McLaury Erosion/Corrosion Research Center, Mechanical Engineering Department, The University of Tulsa, 800 S. Tucker Dr., Tulsa, OK 74104, USA
art ic l e i nf o
a b s t r a c t
Article history: Received 16 September 2014 Received in revised form 22 November 2014 Accepted 27 November 2014
The prediction of erosion damage caused by solid particles within flow lines is crucial for many industries. In most erosion modeling approaches, empirical erosion equations are commonly used to relate particle impact information to erosion magnitude. These equations are usually generated from jet impingement testing in air, since the particle impact speed and angle are assumed not to deviate from conditions in the jet. However, in slurry flows, a wide range of particle impact angles and speeds are produced on the target surface. In this work combining CFD simulation results with experimental data obtained from a normal slurry jet test, an erosion equation has been developed. In this methodology, a computational fluid dynamics (CFD) simulation is used to characterize the particle impact speed, angle and frequency at specific locations on the specimen. Then, the particle impact data are related to the measured erosion depth to achieve an erosion equation from submerged testing. The erosion equation has been validated for oblique impingement configurations and it has been shown that, the equation is well suited for various test conditions and it can successfully predict the local erosion depth. Furthermore, a series of dry impinging jet tests for normal and oblique configurations has been performed. Utilizing a particle image velocimetry (PIV) technique, the slip velocity between the gas and sand particles has been determined. In order to gain a better understanding of the erosion pattern, local erosion depth has been measured using a 3D surface profilometer. The effect of gas velocity and impingement angle on erosion profile has also been investigated. & 2014 Elsevier B.V. All rights reserved.
Keywords: CFD Erosion equation Gas–solid erosion Slurry erosion PIV technique
1. Introduction In many engineering applications, as a result of repetitive impacts of solid particles transported by fluid flow, material is gradually removed from inside walls of piping and equipment. This type of wear is generally called erosion, or more specifically solid particle erosion. The erosion phenomenon is important in many engineering applications including the oil and gas industry, gas turbines, boilers, heat exchangers, fluidized beds and aircrafts operating at low altitudes. In recent years, erosion problems in the oil and gas industry have drawn significant attention amongst researchers, because oil and gas produced from offshore reservoirs may contain a considerable amount of fine sand particles which can lead to severe damage on many industrial components such as pumps, pipes, plugged tees, valves and elbows. This damage can cause leakage and abrupt failure of equipment without prior warning, and can result in expensive repairs and loss of production time. Therefore, it is essential to precisely predict the erosion rate and identify locations which are
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most at risk. Developing a mathematical expression to predict the wear rate is very challenging, since there are many parameters that need to be taken into account. It is well established that among all the parameters, particle impact speed, particle impact angle, particle properties (size, shape, hardness and density) and target material hardness play a significant role in the erosion process. Finnie [1] derived a theoretical erosion equation and proposed that the erosion mechanism in ductile material is due to a cutting process while the mechanism is cracking in brittle material. Thereafter, a wide variety of erosion equations have been developed which are either purely theoretical or empirical based. Bitter [2], Neilson and Gilchrist [3], McLaury et al. [4], Huang et al. [5], Oka et al. [6] and Zhang et al. [7] are among the erosion equations most commonly reported in papers. Meng and Ludema [8] examined a large number of erosion equations mentioned in the literature and concluded that all the erosion equations are only valid for specific conditions and are not suitable for general use. They also found that empirical equations within the range of their test conditions are much more applicable than theoretical ones. Empirical erosion equations are traditionally obtained as a result of a series of tests for normal and oblique impingement of sand particles on a substrate [6,7]. These tests are performed under dry conditions (sand particles in air) where Stokes
http://dx.doi.org/10.1016/j.wear.2014.11.025 0043-1648/& 2014 Elsevier B.V. All rights reserved.
Please cite this article as: A. Mansouri, et al., A combined CFD/experimental methodology for erosion prediction, Wear (2014), http://dx. doi.org/10.1016/j.wear.2014.11.025i
