The Experts below are selected from a list of 30 Experts worldwide ranked by ideXlab platform
Ronald Sachs - One of the best experts on this subject based on the ideXlab platform.
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structural and torsional vibration and noise analysis of a Dry Screw Compressor
Proceedings of the Institution of Mechanical Engineers Part E: Journal of Process Mechanical Engineering, 2017Co-Authors: James Willie, Ronald SachsAbstract:This paper investigates torsional vibration and pulsating noise in a Dry Screw Compressor. The Compressor is designed at Gardner Denver (GD) and is oil-free and use for mounting on highway trucks i...
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Structural and torsional vibration analysis of a Dry Screw Compressor
IOP Conference Series: Materials Science and Engineering, 2015Co-Authors: James Willie, Ronald SachsAbstract:This paper investigates torsional vibration and pulsating noise in a Dry Screw Compressor. The Compressor is designed at Gardner Denver (GD) and is oil free and use for mounting on highway trucks. They are driven using a Power Take-Off (PTO) transmission and gear box on a truck. Torque peak fluctuation and noise measurements are done and their sources are investigated and reported in this work. To accurately predict the torsional response (frequency and relative angular deflection and torque amplitude), the Holzer method is used. It is shown that the first torsional frequency is manifested as sidebands in the gear train meshing frequencies and this can lead to noise that is the result of amplitude modulation. Sensitivity analysis of the drive train identifies the weakest link in the drive train that limits the first torsional frequency to a low value. Finally, the significance of higher mode shapes on inter-lobe clearance distribution of the rotors is investigated.
James Willie - One of the best experts on this subject based on the ideXlab platform.
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structural and torsional vibration and noise analysis of a Dry Screw Compressor
Proceedings of the Institution of Mechanical Engineers Part E: Journal of Process Mechanical Engineering, 2017Co-Authors: James Willie, Ronald SachsAbstract:This paper investigates torsional vibration and pulsating noise in a Dry Screw Compressor. The Compressor is designed at Gardner Denver (GD) and is oil-free and use for mounting on highway trucks i...
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Structural and torsional vibration analysis of a Dry Screw Compressor
IOP Conference Series: Materials Science and Engineering, 2015Co-Authors: James Willie, Ronald SachsAbstract:This paper investigates torsional vibration and pulsating noise in a Dry Screw Compressor. The Compressor is designed at Gardner Denver (GD) and is oil free and use for mounting on highway trucks. They are driven using a Power Take-Off (PTO) transmission and gear box on a truck. Torque peak fluctuation and noise measurements are done and their sources are investigated and reported in this work. To accurately predict the torsional response (frequency and relative angular deflection and torque amplitude), the Holzer method is used. It is shown that the first torsional frequency is manifested as sidebands in the gear train meshing frequencies and this can lead to noise that is the result of amplitude modulation. Sensitivity analysis of the drive train identifies the weakest link in the drive train that limits the first torsional frequency to a low value. Finally, the significance of higher mode shapes on inter-lobe clearance distribution of the rotors is investigated.
Nikola Stosic - One of the best experts on this subject based on the ideXlab platform.
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On heat transfer in Screw Compressors
International Journal of Heat and Fluid Flow, 2015Co-Authors: Nikola StosicAbstract:Heat transfer between the working fluid and machine parts within a Screw Compressor does not affect its performance significantly because the thermal energy dissipation is usually less than 1% of the Compressor power input. However, it can be detrimental to the machine reliability because the fluid compression creates a non-uniform three dimensional temperature field leading to local distortions, which may be larger than the clearances between the machine parts. This phenomenon is widely known and special control procedures are required to allow for start-up and shut down, as well as for steady running operation. These measures are usually derived only from test-bench data and may result in larger clearances than necessary, thereby reducing the optimum performance.This paper gives an outline of two methods of computing heat transfer in a Screw Compressor; namely: by means of a quasi-one dimensional differential model and by three dimensional computational fluid dynamics (CFD). Both methods enable the clearance size for start-up and steady running conditions to be determined. The 3D CFD procedure is more accurate but requires a far longer running time. Two cases are considered: heat transfer in a Dry Screw Compressor where fluid temperatures are high, and an oil-flooded Screw Compressor where fluid temperatures are relatively low but the convective heat transfer coefficient is substantially higher.
Ahmed Shorbagy - One of the best experts on this subject based on the ideXlab platform.
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cfd simulation of a Screw Compressor including leakage flows and rotor heating
Microelectronics Systems Education, 2015Co-Authors: Andreas Spillekohoff, Ja Hesse, Ahmed ShorbagyAbstract:Computational Fluid Dynamics (CFD) simulations have promising potential to become an important part in the development process of positive displacement (PD) machines. CFD delivers deep insights into the flow and thermodynamic behaviour of PD machines. However, the numerical simulation of such machines is more complex compared to dynamic pumps like turbines or fans. The fluid transport in size-changing chambers with very small clearances between the rotors, and between rotors and casing, demands complex meshes that change with each time step. Additionally, the losses due to leakage flows and the heat transfer to the rotors need high-quality meshes so that automatic remeshing is almost impossible.In this paper, setup steps and results for the simulation of a Dry Screw Compressor are shown. The rotating parts are meshed with TwinMesh, a special hexahedral meshing program for gear pumps, gerotors, lobe pumps and Screw Compressors. In particular, these meshes include axial and radial clearances between housing and rotors, and beside the fluid volume the rotor solids are also meshed.The CFD simulation accounts for gas flow with compressibility and turbulence effects, heat transfer between gas and rotors, and leakage flows through the clearances. We show time- resolved results for torques, forces, interlobe pressure, mass flow, and heat flow between gas and rotors, as well as time- and space-resolved results for pressure, velocity, temperature etc. for different discharge ports and working points of the Screw Compressor. These results are also used as thermal loads for deformation simulations of the rotors.
Clayton Russ - One of the best experts on this subject based on the ideXlab platform.
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Dry Screw Compressors In Process Gas Applications Including Maintenance Considerations.
'Biophysical Society of Japan', 1992Co-Authors: Nordquist, Glen B., Bielskus, Peter A., Clayton RussAbstract:LecturePg. 3-20The Dry Screw Compressor, which combines the advantages of positive displacement with rotary motion, is gaining wider international acceptance for process gas applications. The selection of Dry Screw Compressors is dependent upon proper evaluation of the thermodynamic and mechanical characteristics inherent with this type of Compressor. To be discussed are the selection parameters, capabilities, and limitations that must be considered for any process gas Compressor application. The selection parameters include, but are not limited to, the following: • Application range: Flows, pressures and temperatures suited for Screw Compressors as compared to other types of Compressors. • Gas handled: Molecular weight variations, corrosive elements, erosive components, entrained liquids, polymer formation, and other gas characteristics that can best be handled by Dry Screw Compressors. • Process control of flows, pressures and temperatures. • Compliance with recognized design standards, i.e., API, PNEUROP. • Construction features and design parameters that make Dry Screw Compressors suitable for a wide range of applications. This section discusses bearing loading, shaft bending stresses, torsional and lateral vibration analysis, and other mechanical design criteria. The maintenance section of this presentation is intended to offer a broad overview of this equipment and its unique characteristics and special requirements. Particular emphasis will be placed on the restoration of aero performance, which may over extended periods of time deteriorate due to rotor and casing clearance degradation. Topics include predictive and preventative maintenance practices and guidelines, which can extend the useful life of the equipment and minimize unexpected outages, field overhaul techniques, repair shop procedures and rotor and case repairs including welding, coatings, seal stripping, and metal locking
