Developments in analytical wall shear stress modelling for water hammer phenomena

Urbanowicz, Kamil; Bergant, Anton; Stosiak, Michał; Karpenko, Mykola; Bogdevičius, Marijonas

doi:10.1016/j.jsv.2023.117848

Cited by 18 publications

(1 citation statement)

References 39 publications

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“…From expressions ( 6) and ( 7), it follows that the amplitudes of the resonant peaks of the frequency characteristics of the elements of the transfer matrix G(s) decrease at successive resonant frequencies with a slope of the derivative of 10,0 dB/dec, which is consistent with experimental data [23,26]. A sufficiently accurate approximation of the frequency characteristics of the characteristics can be obtained using the transfer matrix G(s) with the following matrix elements [27]:…”

Section: Methodssupporting

confidence: 71%

Modeling of Wave Processes in Hydraulic Drive Systems of Technological Equipment

Ivanchuk,

Belzetskyi,

Ozeranskyi

et al. 2024

JES

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The article, based on the performed theoretical research, solves the essential scientific and technical problem of increasing the accuracy of identification of wave processes in a hydrodynamic system (pipeline) by developing a generalized method of mathematical designing of the dynamics of a continuous viscous and weakly compressed fluid in the hydrodynamic system pipeline based on the Navier-Stokes equation. Amplitude-frequency characteristics represent parameters of wave processes in the hydraulic drive system. A partial solution of Navier–Stokes equations, under zero initial conditions, is proposed in the form of four-pole equations, the components of which are represented in the form of the Laplace image of the corresponding relative pressure and flow coordinates and the the hydraulic line parameters determine the four-pole elements themselves It is also proposed to determine the values of the four-pole elements based on time constants and relative damping coefficients on the frequency characteristics of hydraulic lines with distribution parameters based on the condition of equality of the first resonant frequencies and amplitudes (at these frequencies). With the help of the developed methods, the primary dynamic parameters of the amplitude-frequency characteristics of continuous viscous and weakly compressed liquid in the pipeline of hydraulic systems for different flow ranges. This made it possible to achieve the following practical results: the high degree of adequacy of the developed mathematical model indicates an increase in the reliability of determining the operating characteristics when designing a hydraulic drive. The high accuracy of determining the first resonant frequencies and amplitudes allows for creating a hydraulic pump with improved operational characteristics.

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Section: Methodssupporting

confidence: 71%

Modeling of Wave Processes in Hydraulic Drive Systems of Technological Equipment

Ivanchuk,

Belzetskyi,

Ozeranskyi

et al. 2024

JES

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Unsteady flow rate in transient, incompressible pipe flow

Brumand‐Poor,

Kotte,

Pasquini

et al. 2024

Z Angew Math Mech

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Knowledge regarding current flow rates through pipes and other components is crucial for most hydraulic systems. The hydraulic power can be computed in combination with the pressure, which may be used in many applications, such as predictive maintenance. Most flow rate sensors used in the field of fluid power operate invasively. Therefore, the measurement process itself alters the flow rate. Furthermore, most sensors operate accurately for stationary flow but produce inaccurate measurements for transient flow. A well‐known method of determining the flow rate is to measure the pressure difference between two points along a pipeline and calculate the flow rate based on the law of Hagen and Poiseuille. However, since the relation mentioned above only applies to laminar, steady, and incompressible flow, its usefulness for transient flows is limited. This paper derives a system equation based on the fundamental laws of fluid mechanics, which describe transient, incompressible pipe flow. As a result, the fundamental equations are solved in the Laplace domain and subsequently transformed back into the time domain. The four‐pole theorem relates the pressure difference and the volumetric flow rate. The analytical solution consists of a convolution integral containing a weighting function and the pressure difference. Compared to a simulation, the novel equation displays high accuracy for transient and stationary incompressible pipe flow. This equation paves the way for a soft sensor, which allows the noninvasive measurement of arbitrary volumetric flow rates within pipes.

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Decomposition of the mechanical stress tensor: from the compressible Navier–Stokes equation to a turbulent potential flow model

Di Nucci,

Michele,

Di Risio

2024

Acta Mech

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We frame the mechanical stress tensor decomposition in a general procedure which involves the Helmholtz–Hodge decomposition. We highlight the impact of the mechanical stress tensor decomposition on the Navier–Stokes equation, with emphasis on the dissipation function. For fluids with low compressibility, we draw some insights on the Reynolds Averaged Navier–Stokes equations, and on the Reynolds stress tensor decomposition. We derive a turbulent potential flow model, and investigate the transition from viscous potential flow to turbulent potential flow. Under low Mach number approximation, we apply the turbulent potential flow model to one-dimensional propagation of large amplitude pressure waves in liquid-filled pipe.

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Developments in analytical wall shear stress modelling for water hammer phenomena

Cited by 18 publications

References 39 publications

Modeling of Wave Processes in Hydraulic Drive Systems of Technological Equipment

Modeling of Wave Processes in Hydraulic Drive Systems of Technological Equipment

Unsteady flow rate in transient, incompressible pipe flow

Decomposition of the mechanical stress tensor: from the compressible Navier–Stokes equation to a turbulent potential flow model

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