Strain-based non-intrusive approaches for measuring the pressure of pipes have attracted widespread attention due to their great convenience and ability to avoid destroying the integrity of structures. However, the mentioned method usually measures the dynamic pressure based only on the static strain–pressure sensitivity coefficients (SSSCs) instead of the dynamic strain–pressure sensitivity coefficients (DSSCs) due to its complicated calibration, which will inevitably affect the accuracy significantly. To address this issue, a model-driven scheme with dual stages is proposed in the present study to compensate the dynamic pressure measurement. The DSSCs are analytically derived for the first time from the axial governing equations of the pipe, considering the general boundary conditions for the thin-walled and thick-walled pipes simultaneously. In the first stage, the physical parameters involved in the DSSCs are calibrated by minimizing the residual of the experimental results and the theoretical counterparts. In the second stage, the DSSCs calculated from the calibrated analytical model are utilized to compensate the dynamic pressure based on the relationship between the DSSCs and the SSSCs. The proposed method is applied to an industrial hydraulic pipe system, and the experimental results show that the relative error is reduced greatly after the compensation is implemented, demonstrating the validity of the proposed compensation method.

A Model-Driven Scheme to Compensate the Strain-Based Non-Intrusive Dynamic Pressure Measurement for Hydraulic Pipe

FSI research in pipeline systems – A review of the literature

Vibration analysis and control technologies of hydraulic pipeline system in aircraft: A review

The computer-aided design optimization and vibration analysis, especially avoiding resonance are fundamental challenge to piping system design of complex products. Conventional pipe design methods commonly focus on either automatic geometry layout or vibration analysis, which usually leads to repeated modifications between both disciplines. In this paper, a multi-objective pipe routing algorithm considering vibration performance for aero-engine is presented based on Kriging model and non-dominated sorting genetic algorithm-II (NSGA-II), where pipe length, smoothness, and natural frequency are taken into account. Pipe node positions are optimized by using NSGA-II subject to several constraints. In order to improve computational efficiency, a Kriging model reflecting the relationship between the pipe node position and natural frequency is constructed, and then is applied instead of computer-aided engineering analysis program to evaluate the individual fitness during evolutionary computations. Several numerical computations are performed on a simplified piping model, and the results show that the constructed Kriging model can guarantee high modeling accuracy and the presented routing algorithm is able to obtain a set of non-dominated solutions of pipe layouts, in particular, the natural frequency of pipes are far from engine excitation frequency, which guarantees to avoid possible resonance.

A Pipe Routing Method Considering Vibration for Aero-Engine Using Kriging Model and NSGA-II

This paper investigates the reliability design optimization of an aeronautical hydraulic pipeline system, in which the constraint locations are treated as design parameters. To reduce the size of the optimization problem, two non-probabilistic global sensitivity indices are introduced and modified to screen out those constraint locations which have no or little effect on the optimization target. Considering the rest of constraint locations as design variables, the complexity of the optimization problem is dramatically reduced. The optimization of the pipeline systems demonstrates that the proposed method is superior to the traditional direct optimization method in both the optimization efficiency and results. This work indicates that introduction of sensitivity analysis can greatly improve the efficiency and performance of optimization, especially in those complex engineering problems involving a large number of design variables.

Application of non-probabilistic sensitivity analysis in the optimization of aeronautical hydraulic pipelines

DOI: 10.2514/1.C031660 Inthispaperamodalanalysisofanaircrafthydraulic-pipelinevibrationiscarriedoutconsideringtheinfluenceof the fluid–structure interaction. Aircraft hydraulic pipes are always configured in curved rather than straight lines for the limited aircraft space. Therefore, the influence of curvature and friction of the pipeline should be accounted for in the vibration analysis. A mathematical model is developed to predict the vibration of the selected aircraft hydraulic-pipeline section. Vibration testing of the aircraft hydraulic pipeline is carried out, and comparison between the developed model and test is given, which illustrates that the developed model is correct. The research resultsalsoshowthatthemostimportantfactorfortheresonantfrequencyofthepipelinesectionisitslengthbetween the two supports, which can obviously increase the resonant frequency. The friction influence on the resonant frequency of the pipeline is less than the influence of the curvature. And the friction influence can reduce the stress response range, especially at the pressure peaks.

Modal Analysis of the Aircraft Hydraulic-System Pipeline

Pipeline vibration in aircraft hydraulic systems has drawn more attention in recent years. There are still a lot of problems unresolved in the field, due to the complex non-linearity of fluid–struc...

Two-dimensional stress analysis of the aircraft hydraulic system pipeline

The invention discloses a pulse attenuation plunger pump based on a resistor-capacitor (RC) filter theory. The pulse attenuation plunger pump comprises a plunger pump, a load, an oil tank, a front end cover, a shell, a piston and a spring, wherein the oil outlet of the plunger pump is divided into two paths, one path is connected with the oil tank through the load, and the other path is communicated with a high-pressure oil damping hole on the front end cover of the shell through a pressure oil path; the piston and the spring are arranged in the shell from top to bottom; a low-pressure oil damping hole at the lower end of the shell is connected with an oil leakage port of the plunger pump through a low-pressure oil path and then connected with the oil tank. The pulse attenuation plunger pump has the advantages of simple structure, small volume and light weight and can well attenuate flow pulses generated by various reasons inside the plunger pump; the normal work of the pulse attenuation plunger pump is not influenced by the displacement of the plunger pump; and the pulse attenuation plunger pump is suitable for various constant and variable working conditions.

Pulse attenuation plunger pump based on resistor-capacitor (RC) filter theory

The utility model discloses a pulsation attenuation plunger pump based on the RC (resistor-capacitor) filter principle. The pulsation attenuation plunger pump based on the RC filter principle comprises a plunger pump, a load, an oil tank, a front end cover, a shell, a piston and a spring. An oil outlet of the plunger pump includes two branches. One branch passes by the load and is connected with the oil tank. The other branch is communicated with a high-pressure oil damping hole on the front end cover of the shell. The piston and the spring are disposed in the shell from top to bottom. A low-pressure oil damping hole at the lower end of the shell is connected with an oil leak of the plunger pump prior to being connected with the oil tank. The pulsation attenuation plunger pump based on the RC filter principle is simple in structure, small in size and light in weight, pulsating flows in the plunger pump caused by various reasons can all be well attenuated, and the pulsation attenuation plunger pump can operate without influence of displacement and is applicable to various fixed-displacement or variable-displacement conditions.

Huayong Yang

Papers

Modal Analysis of the Aircraft Hydraulic-System Pipeline

Two-dimensional stress analysis of the aircraft hydraulic system pipeline

Pulse attenuation plunger pump based on resistor-capacitor (RC) filter theory

Pulsation attenuation plunger pump based on RC (resistor-capacitor) filter principle