Experimental analysis and numeric simulation of steady state flow forces on valves of mechatronic pressure regulators for natrual gas powered combustion engines

Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.This paper deals with the experimental analysis and numerical simulation regarding the flow forces of a mechatronical pressure regulator for natural gas powered internal combustion engines. For the experimental analysis a measurement device was constructed to determine these forces as well as other global flow parameters by variation of the pressure ratio and the strokes of the valve gate. The series of tests were simulated on the basis of the Computational Fluid Dynamics (CFD)-code FLUENT. Thereby the model was validated through the comparison of the results deriving from the experimental analysis and the results provided by the numerical simulation. It was shown that the flow forces have a strong dependence on the pressure ratio but are not influenced by the mass flow rate. Accordingly the flow forces are independent of the stroke. By the use of the numerical simulation a visualization of the inner flow characteristics was obtained. Thus the potential for an improvement in the geometry was derived. Besides a generation of eddies in the low and high pressure chamber, backflow occurred in the valve bung as a result of shocks. This took place at low pressure ratios and resulted in a decreasing flow coefficient due to contraction and deceleration of the fluid entering the control edge. At high pressure ratios, a relocation of the flow contraction towards the theoretical flow cross sectional area and a decreasing of the generation and impact of eddies in the valve bung were detected.mp201

Investigations on fluid dynamics of hydraulic accumulators

In state of the art hydrostatic installations accumulators of various designs are implemented to enhance the efficiency or to affect the dynamics of the hydraulic system. The advantages offered by the application of these devices are well known and their thermodynamic properties have been described well in the past. Yet the optimization of their particular performance re-garding fluid dynamics is an existing problem because of the lack of experimental and analytical investigation devices. Whilst operating hydraulic accumulators high dynamic flow rates and velocities including steep pressure gradients are oc-curring so that a special technique had to be created to detect these values. In the Fluid Power Laboratory of Trier University of Ap-plied Sciences a new self developed accumulator test rig re-cently was installed to measure the operating parameters of hy-draulic accumulators with the required high dynamic and accuracy. Special test procedures could be implemented to evaluate and improve especially the performance of the accu-mulators internal flow control valves. The experimental investigations were accompanied by modelling a hydraulic accumulator in a Computational Fluid Dynamic CFD environment where its internal flow phenomena could be simulated successfully. This presentation introduces the new test rig, the developed measuring procedures and the simulation model. Results of high dynamic flow and pressure measurements as well as flow simulations of hydraulic accumulators are shown.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

Method for analysing the heat recovery potential of thermoprocessing equipment

The importance of a heat recovery capability on thermoprocessing systems for increased cost-efficiency is rising steadily, along with energy costs. Accordingly, an increasing number of methods for recovering heat from exhaust gas have emerged in recent years, and the processes in question are being applied to ever more fields. For a plant-related assessment of diverse exhaust gas heat recovery solutions from an economic and/or process engineering viewpoint, it is imperative to analyze the plant-specific energy flows and to present the resulting findings in a clear-cut manner. On the basis of this analysis it is then possible to perform a plant-related evaluation and selection of the most suitable heat recovery method. The present article describes a method that facilitates an economic assessment of the heat recovery potential of thermoprocessing equipment while also permitting a comparison of the plant-specific savings potentials for a given heat recovery process. To this end, a thermodynamic model is first developed to analyze the plant-specific energy flows; this model then enables us to compute these energy flows on the basis of process data. It is further shown how the results are presented in a clearly structured fashion to serve as the basis for further investigation. Next, it is explained how suitable heat recovery solutions can be selected for various equipment results and how the associated savings potentials can be determined. The method is applied, by way of example, to the dataset of an industrial furnace and the results obtained are discussed. It is shown that the method permits an economic evaluation of diverse heat recovery solutions for different plants in day-today operation. In addition, the data analysis provides a capability to detect defective equipment components and unidentified energy flows.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers

Analytische und experimentelle Untersuchung hochbelasteter linienfoermiger Gleitkontakte in einer Fluegelzellenpumpe

Available from TIB Hannover: DW 2889 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Untersuchung des Lasttragevermoegens von Schmierfilmen durch die Ermittlung der physikalischen Bedingungen in Gleit- und Dichtfugen hydraulischer Verdraengereinheiten bei Betrieb mit HFA-Medien Abschlussbericht

SIGLETIB Hannover: FR 4031 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman