Negative Pressures in Modelling Rotating Polymer Processing Machinery Are Meaningless, But They Are Telling Something
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A. Goger
Abstract
In the technical literature, some authors have reported calculation of negative pressures in simulations of twin screw extrusion and other types of processing, without giving any explanations. In the majority publications there is no mention of such meaningless results, even though theoretical considerations indicate that negative pressures could be obtained in the expansion region of drag flows through narrow non-parallel surfaces. The meaningless negative pressures are due to the application of single fluid theory to flow regions where bubbles would form, when the pressure drops below the vapor pressure of the liquid. This has been known for a long time from the study of lubrication bearings and related cavitation phenomena. It is argued that the boundary conditions should be carefully chosen for avoiding results in numerical simulations, which can never be reconciled with experimental pressure data.
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© 2014, Carl Hanser Verlag, Munich
Artikel in diesem Heft
- Contents
- Contents
- Regular Contributed Articles
- The Processing Behavior of Liquid Sn/Molten Polyethylene during Internal Mixing
- Study on Packing Phase Control Based on the Cavity Pressure-Temperature during Injection Molding
- Synthesis and Properties of a Novel Intumescent Flame Retardant and its Application in LLDPE
- The Mechanism of Neck-in Phenomenon in Film Casting Process
- Morphology, Mechanical and Thermal Properties of Recycled PC/ABS Blends Processed via Vane Extruder
- Thermal Conductivity of Polypropylene Composites with Combined Boron Nitride Fillers
- Characterization on Biodegradation of Enzymatically Synthesized Polylactic Acid by Using Alkaline Protease and Lipase
- Numerical Investigation and Experimental Observation of Extrudate Swell for Viscoelastic Polymer Melts
- Processing and Wear Analysis of Blast Furnace Slag Filled Polypropylene Composites Using Taguchi Model and ANN
- Microchannel Deformation of Polymer Chip in In-Mold Bonding
- Synthesis and Characteristics of Graft Copolymerization of Starch-G-PAM Using A Twin-Roll Mixer as Reactor for Cornstarch with Different Amylose/Amylopectin Ratios
- Experimental Investigation of PC-Films Using Optical Measurements
- Effect of Compounding Conditions on Static and Dynamic Mechanical Properties of High Density Polyethylene/Ground Tire Rubber Blends
- Effect of Feeding Strategy on the Mechanical Properties of PP/Recycled EPDM/PP-G-MA Blends
- Synthesis and Characterization of Chitosan & Amino Acid Superabsorbent Hydrogels
- Rapid Communications
- Negative Pressures in Modelling Rotating Polymer Processing Machinery Are Meaningless, But They Are Telling Something
- PPS News
- PPS News
- Seikei-Kakou Abstracts
- Seikei-Kakou Abstracts
Artikel in diesem Heft
- Contents
- Contents
- Regular Contributed Articles
- The Processing Behavior of Liquid Sn/Molten Polyethylene during Internal Mixing
- Study on Packing Phase Control Based on the Cavity Pressure-Temperature during Injection Molding
- Synthesis and Properties of a Novel Intumescent Flame Retardant and its Application in LLDPE
- The Mechanism of Neck-in Phenomenon in Film Casting Process
- Morphology, Mechanical and Thermal Properties of Recycled PC/ABS Blends Processed via Vane Extruder
- Thermal Conductivity of Polypropylene Composites with Combined Boron Nitride Fillers
- Characterization on Biodegradation of Enzymatically Synthesized Polylactic Acid by Using Alkaline Protease and Lipase
- Numerical Investigation and Experimental Observation of Extrudate Swell for Viscoelastic Polymer Melts
- Processing and Wear Analysis of Blast Furnace Slag Filled Polypropylene Composites Using Taguchi Model and ANN
- Microchannel Deformation of Polymer Chip in In-Mold Bonding
- Synthesis and Characteristics of Graft Copolymerization of Starch-G-PAM Using A Twin-Roll Mixer as Reactor for Cornstarch with Different Amylose/Amylopectin Ratios
- Experimental Investigation of PC-Films Using Optical Measurements
- Effect of Compounding Conditions on Static and Dynamic Mechanical Properties of High Density Polyethylene/Ground Tire Rubber Blends
- Effect of Feeding Strategy on the Mechanical Properties of PP/Recycled EPDM/PP-G-MA Blends
- Synthesis and Characterization of Chitosan & Amino Acid Superabsorbent Hydrogels
- Rapid Communications
- Negative Pressures in Modelling Rotating Polymer Processing Machinery Are Meaningless, But They Are Telling Something
- PPS News
- PPS News
- Seikei-Kakou Abstracts
- Seikei-Kakou Abstracts
