Measurement-integrated simulation of wall pressure measurements using a turbulent model for analyzing oscillating orifice flow in a circular pipe

Nakao, Mitsuhiro; Kawashima, Kenji; Kagawa, Toshiharu

doi:10.1016/j.compfluid.2011.05.012

Cited by 8 publications

(4 citation statements)

References 14 publications

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“…Measurement-integrated (MI) simulation using a turbulent model was proposed and applied to steady and unsteady oscillatory airflows passing an orifice plate in a pipeline. Velocity and pressure feedbacks were conducted and results with both feedback methods showed good agreement with the experimental results (Nakao et al 2009(Nakao et al , 2011.…”

Section: State Observersmentioning

confidence: 53%

Numerical simulation of real-world flows

Hayase

2015

Fluid Dyn. Res.

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Obtaining real flow information is important in various fields, but is a difficult issue because measurement data are usually limited in time and space, and computational results usually do not represent the exact state of real flows. Problems inherent in the realization of numerical simulation of real-world flows include the difficulty in representing exact initial and boundary conditions and the difficulty in representing unstable flow characteristics. This article reviews studies dealing with these problems. First, an overview of basic flow measurement methodologies and measurement data interpolation/ approximation techniques is presented. Then, studies on methods of integrating numerical simulation and measurement, namely, four-dimensional variational data assimilation (4D-Var), Kalman filters (KFs), state observers, etc are discussed. The first problem is properly solved by these integration methodologies. The second problem can be partially solved with 4D-Var in which only initial and boundary conditions are control parameters. If an appropriate control parameter capable of modifying the dynamical structure of the model is included in the formulation of 4D-Var, unstable modes are properly suppressed and the second problem is solved. The state observer and KFs also solve the second problem by modifying mathematical models to stabilize the unstable modes of the original dynamical system by applying feedback signals. These integration methodologies are now applied in simulation of real-world flows in a wide variety of research fields. Examples are presented for basic fluid dynamics and applications in meteorology, aerospace, medicine, etc.

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Section: State Observersmentioning

confidence: 53%

Numerical simulation of real-world flows

Hayase

2015

Fluid Dyn. Res.

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“…気体管路における圧力の計測は，制御や管理，現象解析の観点から重要である．例えば都市ガスパイプラインにおいてガスの安定供給のために用いられるガスガバナは自力式の構造であるために圧力変動の影響を受けやすく，管路内の圧力脈動の解析が重要である (1) ．特に家庭用都市ガスでは供給圧が約 2 kPaG であり，このような低圧の管路内では微小振幅波が発生することが知られている (2) ．気体管路は分布定数系であり，時空間的に分布する圧力を計測するためには多数のセンサが必要となるが多数のセンサの設置は現実的ではなく，また計測したい位置にセンサを取り付けられるとは限らない．一方，数値計算では圧力分布を得ることが容易であり，気体管路過渡応答の数値計算に関する研究 (3) がなされている．しかし，計算解はセンサの計測ノイズや計算の初期条件や境界条件の誤差の影響を直接受けてしまい，実現象の再現が難しい．そこで多くの場合計測できる少数の計測点圧力を用いて，数値計算の援用により管路内の状態分布を推定できれば便利である．数値計算と計測の融合による分布的状態推定法はデータ同化と呼ばれ，気象分野を中心に盛んに研究されており (4) ，4 次元変分法 (5) やカルマンフィルタ (6) ，計測融合シミュレーション (7) (8) など様々な方法について研究されている．その中でもカルマンフィルタは既存の計算コードを流用しやすい利点があり，油圧管路では有限要素法にカルマンフィルタを適用することで数値モデルや初期条件の誤差を補償できることが示されている (9)…”

Section: 緒言unclassified

Estimation of Small Amplitude Pressure Wave in Gaseous Pipeline Using a Linear Kalman Filter

2013

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Measurement of pressure distribution in gaseous pipeline is important from a view point of control or safe management. In the present paper, a linear Kalman filter is developed to estimate the pressure estimation of small amplitude pressure wave in a single straight gaseous pipeline with constant circular cross section. The Kalman filter uses the linear dynamic system of the pipeline derived by using the approximation method of the unsteady friction, high speed and accurate computing method. The inputs to the Kalman filter are inlet and outlet pressures, and the pressure at the point one third of the pipe entrance is used as the observation point for feedback compensation. The performance of the developed method is tested using two experimental results by comparing with calculation results without feedback compensation. The comparison demonstrated that the developed method has better performance in the presences of measurement noise and erroneous boundary condition than does the ordinary calculation. It also showed much higher ability in error reduction than the ordinary calculation in computation with an erroneous initial condition.

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“…Li et al [16] indirectly estimated the suction force of a vacuum gripper (swirling air type) by measuring the film pressure distribution. Nakao et al [17] suggested a measurement integrated simulation method to investigate unsteady flow through an orifice in a pipe.…”

Section: Introductionmentioning

confidence: 99%

Integration of measurement and simulation of film pressure for estimating deformation of a glass sheet on a noncontact air conveyor

Yang¹,

Zhong²,

Wang³

et al. 2020

Mech. Eng. Sci.

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Recently, large and thin glass substrates are transported by air film conveyors to reduce surface damage. On the production line, the glass substrates are desired to be transported flatly on the conveyor to ensure the quality inspection. A method by feedbacking film pressure to the theoretical model is proposed for estimation of the deformation of the glass sheet, and the validity of the method is theoretically and experimentally verified. First, a theoretical model including the flow behavior through a porous-walled gap is established, and the film pressure distribution can be predicted by solving the model. Then, an experimental setup that can simultaneously measure the film pressure and the flatness of the glass sheet is established, and, the validity of the model is verified experimentally. Next, with the pressure points at the grooves as the boundary and the pressure points at the flange area as the feedback, an algorithm is applied to shape the one-dimensional deformation at the centerlines in accordance with a quadratic curve. Furthermore, two-dimensional deformation of the glass sheet can then be estimated by an interpolation operation. Comparisons of the calculated results with the experimental data verify the effectiveness of the estimating method.

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Measurement-integrated simulation of wall pressure measurements using a turbulent model for analyzing oscillating orifice flow in a circular pipe

Cited by 8 publications

References 14 publications

Numerical simulation of real-world flows

Numerical simulation of real-world flows

Estimation of Small Amplitude Pressure Wave in Gaseous Pipeline Using a Linear Kalman Filter

Integration of measurement and simulation of film pressure for estimating deformation of a glass sheet on a noncontact air conveyor

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