Numerical Simulation of Compressible Multi-Phase Flow in High Pressure Fuel Pump

2014 ◽  
Author(s):  
Frank Husmeier ◽  
David Greif ◽  
Peter Sampl ◽  
Jure Strucl ◽  
Wilfried Edelbauer
Keyword(s):  
High Pressure ◽  
Liquid Fuel ◽  
Load Condition ◽  
Elevated Pressure ◽  
Pressure Level ◽  
Multiphase Model ◽  
Local Pressure ◽  
Local Flow ◽  
Fuel Pump ◽  
Moving Parts

Modern injection systems utilize high injection pressures to enhance the break-up of the injected fuel and the mixing of fuel with air. Elevated pressure level targets high performance, high efficiency and low tailpipe emissions. Such conditions lead to high internal loads of fuel injection equipment and aggressive conditions within fuel injectors and pumps. The high pressure pump is the most critical component assuring appropriate elevated pressure level. Under certain conditions cavitation can occur within the system, which will affect the performance of the pump and in long term also its durability. Namely, cavitation repeatedly appearing at the same location can lead to erosion damage, which is clearly not desired. Therefore, numerical analyses by means of Computational Fluid Dynamics (CFD), represent a powerful tool in the early stage of component definition or design of the pump itself. As the pressure appearing in such systems exceeds 300 MPa, the liquid fuel needs to be treated as compressible. Moving parts of the investigated fuel pump are displaced due to pressure forces, which means that pressure variations and pressure waves need to be accurately predicted in order to predict accurate part displacements and correct wetted volume shape. In order to achieve this, the liquid fuel is treated as compressible, otherwise exact inlet- and outlet check-valve displacements are not predictable. In present work the liquid compressible Euler-Eulerian multiphase model of the commercial CFD code AVL FIRE® has been applied. The domain has been geometrically discretized using the preprocessing part of the applied CFD tool, moving parts have been handled by a novel, so-called “mesh deformation by formula” methodology. The advantage of the approach is that it does not require the pre-definition of all moving parts but allows for an arbitrary, user-defined movement of all mesh nodes. The motion of internal floating parts is performed automatically during the calculation according to the local pressure forces. Due to high pressure levels local flow velocities are typically very high causing the fuel to undergo phase change from liquid to vapor called cavitation. To accurately account for the effect of cavitation, the applied CFD code offers advanced cavitation modeling options. The applied capability enables estimation of flow aggressiveness and the probability for the onset of cavitation erosion on the surface of the components with the objective to optimize or entirely eliminate cavitation. In the present study two simulations have been performed; (i) part load and (ii) full load condition.

Influence of Geometric Imperfections on Aerodynamic and Aeroelastic Behavior of a Compressor Blisk

2017 ◽  
Author(s):  
Christian Keller ◽  
Andreas Kellersmann ◽  
Jens Friedrichs ◽  
Joerg R. Seume
Keyword(s):  
High Pressure ◽  
Numerical Study ◽  
Leading Edge ◽  
Mode Shapes ◽  
Local Pressure ◽  
Torsional Mode ◽  
Local Flow ◽  
Geometric Imperfections ◽  
Geometrical Properties ◽  
Aerodynamic Properties

Impacts of foreign objects can cause cracks and dents in airfoils, especially in the leading edge. The regeneration of high-pressure compressors blisks with current repair methods is often restricted to a local blending of these edges. This can cause significant changes in the airfoils’ geometrical properties, which in turn influence their aerodynamic and aeroelastic characteristics. Changes at the leading edge have a particularly strong influence on the airfoils’ aerodynamic properties. In order to be able to make an informed decision about if and how a repair should be performed, consequences have to be predicted in advance. To investigate their influence on the aerodynamic and aeroelastic behavior, typical blend repairs are applied to the geometry of a blisk in a 1.5-stage research axial compressor [1], which are representative in shape and size. Blisks (Blade-Integrated-diSK) are function integrated components, which are expected to have a high life span due to significant costs in design and production. Similar modifications are implemented at different radial heights of the blades, in order to investigate the influence of location and penetration depth of blend repairs. It is assured that only the blend repair region is modified while the rest of the blade stays in the original shape. Thus, a realistic change of the geometry is given. The numerical study presented here deals with the influence of geometric imperfections, blend repairs in particular, on the aerodynamic and aeroelastic behavior of the high pressure compressors blisks. Results show that blend repairs have an influence on the local pressure distribution as well as on the local flow turning. Even though the leading edge is reshaped during repair, performance degradation can be observed. Furthermore, the working range of the compressor stage is influenced by the blend-repairs, which is of great importance for safe operation. Finally, the local changes in aerodynamics and blade deformation influence the aeroelastic behavior. This influence depends on the investigated mode shape and the location of the modification. The closer the modification is located towards the tip, the more pronounced are the shifts in aerodynamic damping and aerodynamic stiffness. Low torsional mode shapes display the highest sensitivity to the modifications.

scholarly journals The effect of high pressure treatment on the quality of chicken breast meat

2020 ◽  
Vol 14 (3-4) ◽  
pp. 76-81
Author(s):  
Nives Marušić Radovčić ◽  
Damir Ježek ◽  
Ksenija Markov ◽  
Jadranka Frece ◽  
Duška Ćurić ◽  
...  
Keyword(s):  
High Pressure ◽  
Treatment Time ◽  
Elevated Pressure ◽  
Quality Parameters ◽  
High Pressure Processing ◽  
Chicken Breast ◽  
Moisture Uptake ◽  
Breast Meat ◽  
Chicken Breast Meat ◽  
Cooking Yield

In the present work, the effect of high pressure processing (HPP) (0, 100, 200 and 300 MPa) and different treatment time (5 and 10 minutes) on the moisture uptake, cooking yield, colour and texture, as well as microbial population of chicken breast fillets was investigated. The application of high hydrostatic pressure resulted in a modification of quality parameters of chicken breast meat. By increasing pressure and time of the treatment the moisture uptake was reduced: samples treated with 300 MPa for 10 min had the lowest moisture uptake values. Cooking yield was not affected by HPP treatments. Increased pressure affected the colour by increasing L*, a* and b* values (only HPP treatment of 100 MPa in duration of 5 and 10 minutes did not affect colour of chicken breast meat). Lower pressures (100 and 200 MPa) tenderized, whereas elevated pressure (300 MPa) increased hardness in chicken breast fillets. Higher level of pressure (300 MPa) reduced bacteria count by about 3.0 – 5.3 log (CFU/g), depending on the microorganism and duration of the process.

Use of powdered steel ROM2F3S-MP for high pressure fuel pump injector nozzle needles

1989 ◽  
Vol 31 (10) ◽  
pp. 784-788
Author(s):  
A. P. Gulyaev ◽  
L. P. Sergienko ◽  
V. N. Filimonov ◽  
A. N. Mishchenko
Keyword(s):  
High Pressure ◽  
Fuel Pump ◽  
Injector Nozzle ◽  
Powdered Steel

scholarly journals In situ observation of phase changes of a silica-supported cobalt catalyst for the Fischer–Tropsch process by the development of a synchrotron-compatible in situ/operando powder X-ray diffraction cell

2018 ◽  
Vol 25 (6) ◽  
pp. 1673-1682 ◽  
Author(s):  
Adam S. Hoffman ◽  
Joseph A. Singh ◽  
Stacey F. Bent ◽  
Simon R. Bare
Keyword(s):  
High Pressure ◽  
Elevated Pressure ◽  
Phase Changes ◽  
In Situ Observation ◽  
X Ray Diffraction ◽  
Fischer Tropsch ◽  
X Ray ◽  
And Performance ◽  
Co Nanoparticles

In situ characterization of catalysts gives direct insight into the working state of the material. Here, the design and performance characteristics of a universal in situ synchrotron-compatible X-ray diffraction cell capable of operation at high temperature and high pressure, 1373 K, and 35 bar, respectively, are reported. Its performance is demonstrated by characterizing a cobalt-based catalyst used in a prototypical high-pressure catalytic reaction, the Fischer–Tropsch synthesis, using X-ray diffraction. Cobalt nanoparticles supported on silica were studied in situ during Fischer–Tropsch catalysis using syngas, H2 and CO, at 723 K and 20 bar. Post reaction, the Co nanoparticles were carburized at elevated pressure, demonstrating an increased rate of carburization compared with atmospheric studies.

scholarly journals FabF Is Required for Piezoregulation ofcis-Vaccenic Acid Levels and Piezophilic Growth of the Deep-Sea Bacterium Photobacterium profundum Strain SS9

2000 ◽  
Vol 182 (5) ◽  
pp. 1264-1271 ◽  
Author(s):  
Eric E. Allen ◽  
Douglas H. Bartlett
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Deep Sea ◽  
Unsaturated Fatty Acids ◽  
Acyl Carrier Protein ◽  
Vaccenic Acid ◽  
Bacterial Species ◽  
Elevated Pressure ◽  
Wild Type ◽  
Photobacterium Profundum

ABSTRACT To more fully explore the role of unsaturated fatty acids in high-pressure, low-temperature growth, the fabF gene from the psychrotolerant, piezophilic deep-sea bacteriumPhotobacterium profundum strain SS9 was characterized and its role and regulation were examined. An SS9 strain harboring a disruption in the fabF gene (strain EA40) displayed growth impairment at elevated hydrostatic pressure concomitant with diminishedcis-vaccenic acid (18:1) production. However, growth ability at elevated pressure could be restored to wild-type levels by the addition of exogenous 18:1 to the growth medium. Transcript analysis did not indicate that the SS9 fabF gene is transcriptionally regulated, suggesting that the elevated 18:1 levels produced in response to pressure increase result from posttranscriptional changes. Unlike many pressure-adapted bacterial species such as SS9, the mesophile Escherichia coli did not regulate its fatty acid composition in an adaptive manner in response to changes in hydrostatic pressure. Moreover, an E. coli fabF strain was as susceptible to elevated pressure as wild-type cells. It is proposed that the SS9 fabF product, β-ketoacyl–acyl carrier protein synthase II has evolved novel pressure-responsive characteristics which facilitate SS9 growth at high pressure.

scholarly journals A study on the causes of the destruction of the high pressure hoses during operation and cyclic tests

2019 ◽  
pp. 76-79
Author(s):  
I. V. Borisovets ◽  
T. P. Kurenkova
Keyword(s):  
High Pressure ◽  
Liquid Fuel ◽  
Mineral Oil ◽  
The Other ◽  
Cyclic Tests ◽  
Electron Microscopic ◽  
Premature Failure ◽  
Water Emulsion ◽  
Management Company ◽  
High Flexibility

High pressure hose (HPH) is a flexible pipeline for the transportation of special hydraulic and motor fluids based on mineral oil, liquid fuel, grease or water emulsion under pressure, to transfer the working force. Structurally, the sleeve is two or more rubber tubes placed one into the other, reinforced with metal braids or coils, equipped with connecting fittings [1]. HPH is characterized by a sufficiently high flexibility in combination with the ability to withstand significant pressure.In cases of premature failure of high-pressure hoses during cyclic or impulse tests, the cause of the nonconformity must be determined. The article describes the main stages of the study of defective high-pressure hoses in determining the cause of their failure and provides examples of studies using visual, metallographic, electron microscopic methods of analysis in the metallographic laboratory of OJSC «BSW – Management Company of Holding «BMC».

Under Pressure: High-Pressure Metamorphism in the Alps

Elements ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Lucie Tajčmanová ◽  
Paola Manzotti ◽  
Matteo Alvaro
Keyword(s):  
High Pressure ◽  
Structural Data ◽  
Metamorphic Rocks ◽  
Lithostatic Pressure ◽  
Mineral Inclusion ◽  
Crustal Material ◽  
Local Pressure ◽  
Ultra High Pressure ◽  
Mechanical Models ◽  
The Alps

The mechanisms attending the burial of crustal material and its exhumation before and during the Alpine orogeny are controversial. New mechanical models propose local pressure perturbations deviating from lithostatic pressure as a possible mechanism for creating (ultra-)high-pressure rocks in the Alps. These models challenge the assumption that metamorphic pressure can be used as a measure of depth, in this case implying deep subduction of metamorphic rocks beneath the Alpine orogen. We summarize petro-logical, geochronological and structural data to assess two fundamentally distinct mechanisms of forming (ultra-)high-pressure rocks: deep subduction; or anomalous, non-lithostatic pressure variation. Furthermore, we explore mineral-inclusion barometry to assess the relationship between pressure and depth in metamorphic rocks.

CAE Correlation of Sealing Pressure of a Press-in-Place Gasket

2021 ◽  
Keyword(s):  
Internal Pressure ◽  
Pressure Distribution ◽  
Load Condition ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Test Results ◽  
Local Pressure ◽  
Cross Sectional ◽  
Pad Test ◽  
Sealing Pressure

The Press-in-Place (PIP) gasket is a static face seal with self-retaining feature, which is used for the mating surfaces of engine components to maintain the reliability of the closed system under various operating conditions. Its design allows it to provide enough contact pressure to seal the internal fluid as well as prevent mechanical failures. Insufficient sealing pressure will lead to fluid leakage, consequently resulting in engine failures. A test fixture was designed to simulate the clamp load and internal pressure condition on a gasket bolted joint. A Sensor pad using TEKSCAN equipment was used to capture the overall and local pressure distribution of the PIP gasket under various engine loading conditions. Then, the Sensor pad test results were compared with simulated CAE results from computer models. Through the comparisons, it is found that the gasket sealing pressure of test data and CAE data show good correlation for bolt load condition 500N when compared to internal pressure side load condition of 0.138 MPa & 0.276 MPa. Moreover, the gasket cross-sectional pressure distribution obtained by experimental tests and CAE models correlated very well with R2 ranging from 90 to 99% for all load cases. Both CAE and Sensor pad test results shows increase in sealing pressure when internal side pressure is applied to the gasket seal.

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