Resonance reliability and importance measure analysis of multi-span pipe conveying fluid embedded in temperature-varying matrix

Pipe system conveying fluid faces the problem of multi-order resonance failure caused by broadband excitation. For solving above problem, the dynamic stiffness method is employed to solve the dynamic equations of multi-span pipes considering the temperature effect. Combining the obtained natural frequency and the rule of resonance failure of pipe system, a multi-order anti-resonance system reliability model is established in this paper. To analyze the effect of input variable uncertainty on the probability of system resonance failure, the variance-based importance measurement index is further established. By introducing the active learning Kriging (ALK) model, the resonance failure probability and importance measurement index can be calculated efficiently. The effects of fluid flow velocity, pressure and temperature on the probability of pipe resonance failure are analyzed in detail, which has significant guidance for the anti-resonance optimization design of pipes.

Exhaust Prototype Design of L12B Engine

The CFD simulation test carried out on the prototype exhaust, produce an average fluid flow velocity value of 8.36 m/s, and the experimental test results using a flowbench engine on the prototype exhaust, produce an average fluid flow velocity value of 8.49 m/s, so the errorcomparison from themeasurement results on the prototype exhaust between the CFD simulation and experimental results is 1.53%. Fluid flow velocity is a measurement reference in this study because it directly affectsthe scavenging effect on the internal combustion engine, which of course will directly affect the level of power generated by the engine.

Thermal-Hydraulic Performance Analysis by Means of Rectangular Winglet Vortex Generators in a Channel: An Experimental Study

Vortex generators (VGs) are one of the effective passive models used to increase the heat transfer rate in heat exchangers. In this experiment, heat transfer from six cylinders heated to the airflow was improved by attaching rectangular winglet vortex generators (RWVGs) to a plate in a rectangular channel. The installation aimed to increase the value of the thermal-hydraulic performance evaluation criteria in the line. This experimental study was carried out by varying the fluid flow velocity from 0.4 m/s to 2 m/s with an interval of 0.2 m/s in the channel. Three pairs of VGs were arranged in both in-line and staggered configurations. The experimental results show that the thermal-hydraulic performance evaluation criteria for three pairs of vortex generators in the staggered configuration was 15.17% higher than the baseline, while the thermal-hydraulic performance of the in-line arrangement was 1.54% higher than the staggered one.

Design and analysis of a water-cooling system in a new YASA in-wheel motor for electric vehicles

An in-wheel motor, as a key part of an in-wheel driving system, needs to satisfy strict restriction on thermal balance for increasingly high-power density in limited space and weight. Therefore, a new in-wheel motor with an innovative water-cooling system for one newly developed electric vehicle was developed. Based on mechanical structure of the motor, all potential water-cooling layouts were firstly designed with consideration of mechanical strength and manufacturability. A thermal conjugate simulation model of the developed in-wheel motor was then built and its thermally fluid-solid interactions were investigated in this study. All potential water-path layouts of the motor were compared regarding cooling effect and fluid resistance, which impact performance of the motor. Fluid flow velocity and fluid state, determined by the water-path layout, significantly impact cooling effect of the motor. The well-designed water-cooling system significantly reduces motor's temperature at a low cost on required coolant driven pressure which benefits the efficiency of the developed motor. A prototype of the developed motor with the optimal water-path layout was built and tested on the test rig. The developed motor provides outstanding thermal performance.

The Dissipative Properties Assessment of the Oscillatory System of a Serial Sample of the Coriolis Flowmeter

The quantitative estimates of the flow rate (or density) of the flowing fluid obtained by the measurements using the industrial Coriolis flowmeters are made by using the laboratory experiments previously performed with the exemplary sensor. In this case we face two limitations, such as the unavailability of the facilities because of intense laboratory schedules and little time to upgrade the sensor oscillatory system. So we suggest using the virtual prototyping approaches as an alternative to the descriptive approaches. One of the fundamental problems of creating a virtual prototype of the Coriolis flowmeter is to separate the main parameter measured by the flowmeter (the phase shift) into the parts connected to the gyroscopic and dissipative forces. To solve this problem, we need to identify the dissipative forces model of the flowmeter oscillatory system. The article discusses the experimental results determining the dissipative properties of the mechanical oscillatory system of one of the commercially available Coriolis flowmeter samples. The algorithm identifying the model of the dissipative properties of the flowmeter oscillatory system is based on studying the nonlinearity degree of the envelope of the vibrogram of free damped oscillations. The experiments were carried out at the pouring stand of the Center for Experimental Mechanics of the South Ural State University, which allows controlling the speed and phase composition of the fluid flowing through the flowmeter. The article describes the processing algorithms for vibrograms of the damped oscillations, which make it possible to isolate the contribution into the dissipated energy from the dry (Coulomb model), the linear viscous (Rayleigh model) and quadratic viscous friction. The pronounced dependence of the vibrational system dissipation of the Coriolis flowmeter on the features of the fluid flow (velocity, mode: continuous, slug) was experimentally proven, the solutions of identifying the model of the dissipative forces are presented. The identification algorithm for the model of the dissipative properties of the flowmeter oscillatory system is based on studying the nonlinearity degree of the envelope of the vibrogram of the free damped oscillations. The use of the pouring stand made it possible to control the speed and phase composition of the fluid flowing through the flowmeter. The article describes the processing algorithms for the vibrograms of the damped oscillations by isolating the contribution into the dissipated energy from the dry (Coulomb model), linear viscous (Rayleigh model) and quadratic viscous friction. The pronounced dependence of the dissipation of the vibrational system of the Coriolis flowmeter on the features of the fluid flow (velocity, mode: continuous, slug) was experimentally proved, and the results of identifying the model of the dissipative forces are presented. The experiments included water acts as a fluid medium and air acts as a dispersed phase.

Investigation of fluid flow velocity within the intervertebral disc

Enhancing fluid flow velocity within the intervertebral disc may allow to increase solute transportation rates and improve disc nutrition as the sufficient supply of the nutrients to cells of intervertebral disc is a key factor in order to avoid or delay processes of disc degeneration. Poroelastic finite element model of lumbar intervertebral disc is used to calculate fluid flow velocity with the intervertebral disc due to flexion, extension, lateral bending and axial rotation. When comparing the average of flow velocity, the highest values are calculated when flexion and extension moments were applied to the disc, but lateral bending induces the highest value of velocity component in Y direction in nucleus pulposus, yet the assumption that lateral bending could be more beneficial in order to improve nutrients supply to intervertebral disc cannot be substantiated only by this data, as calculated values of velocity component Y are significantly lower that total velocity values.

Determination of Dynamic Drainage Volume in Water-Flood Operations Based on Fluid Flow Velocity Field Delineation

Dynamic drainage volume is a useful measure in evaluating well completions, well spacing, and water-flood operations. It is usually approximated with a two-dimensional circle or a three-dimensional (3D) box that encloses a well using empirical correlations and production/injection volumes. While this approximation may be convenient, it certainly is not a good estimation for the effective and dynamic drainage volume, which is key for improved recovery. This paper proposes a new method to compute dynamic drainage volumes based on reservoir simulation results. A 3D fluid flow velocity field is first generated and then visualized as a function of time. Through velocity thresholding, one can delineate flow regions, and accurately and parsimoniously determine well drainage in water-flood operations. Our new method was proven to be more efficient and practical as demonstrated in a field-based synthetic model with nine injectors and 16 producers formed as an inverted five-spot water-flood pattern commonly used in the field, and a benchmark SPE 9 model. The novelty of the method lies in that a 3D fluid velocity field is generated to determine dynamic drainage volume. Our new method could be applied to optimize well placement and improve well operation, and finally increase the production in a heuristic, instructive, and cost-effective manner to maximize the estimated ultimate recovery.