Structural Dynamics and Aeroelasticity of Airborne Diesel Engine Turbochargers

2019 ◽  
Author(s):  
Ryan C. McGowan ◽  
Muthuvel Murugan ◽  
Michael T. Szedlmayer ◽  
Kenneth S. Kim ◽  
Kurt M. Kruger ◽  
...  
Keyword(s):  
Structural Dynamics ◽  
Flow Rate ◽  
Failure Modes ◽  
Stress Measurement ◽  
Operating Conditions ◽  
Ground Vehicles ◽  
Blade Vibration ◽  
Physical Mechanisms ◽  
Bending Modes ◽  
Solid Dynamics

Abstract Compared to turbodiesel technology for ground vehicles, the increasing application of turbochargers in aircraft diesel engines presents a unique set of structural dynamics and aeroelasticity considerations due to their more extreme operating conditions. In particular, blade vibration and flutter are two related but distinct phenomena that impact the design of these turbochargers and reliable operation over their lifetime. Deformation or fatigue due to blade excitation can reduce efficiency or cause components to fail prematurely. The existing literature on turbomachinery covers many research efforts to analyze these phenomena by investigating the physical mechanisms responsible as well as the relationships between the fluid and solid dynamics. This review paper emphasizes those efforts most relevant to airborne diesel turbochargers, including research focusing on altitude effects on centrifugal compressors. Early work in which the dominant parameters for modeling turbocharger behavior were identified is highlighted as are current efforts to develop higher-fidelity models. An overview of existing and proposed techniques for measuring and controlling blade resonance is also given. Finally, an experimental facility for testing of turbochargers is proposed. The facility will include a nonintrusive stress measurement system and enable measurement of blade deflection/vibration together with blade stress, temperature, pressure, and flow rate across a range of simulated altitudes. The goal will be to characterize the blade bending modes, resonances, and critical speeds for various simulated altitude, pressure, temperature, and flow rate conditions so that designs may be devised that could prevent or avoid the associated failure modes in airborne diesel applications.

Stabilization of the Speed of the Hydraulic Motor Through Throttle Compensation for Volume Losses

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Operating Conditions ◽  
Drive System ◽  
Inlet Pressure ◽  
Schematic Diagram ◽  
Hydraulic Characteristics ◽  
Hydraulic Motor ◽  
Flow Through

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

scholarly journals Chemical–Electrochemical Process Concept for Lead Recovery from Waste Cathode Ray Tube Glass

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1546
Author(s):  
Árpád Imre-Lucaci ◽  
Melinda Fogarasi ◽  
Florica Imre-Lucaci ◽  
Szabolcs Fogarasi
Keyword(s):  
Flow Rate ◽  
Current Density ◽  
Complete Recovery ◽  
Electrochemical Process ◽  
Operating Conditions ◽  
General Effect ◽  
Optimal Operating ◽  
Recirculation Flow ◽  
Lead Recovery ◽  
Cathode Ray Tube

This paper presents a novel approach for the recovery of lead from waste cathode-ray tube (CRT) glass by applying a combined chemical-electrochemical process which allows the simultaneous recovery of Pb from waste CRT glass and electrochemical regeneration of the leaching agent. The optimal operating conditions were identified based on the influence of leaching agent concentration, recirculation flow rate and current density on the main technical performance indicators. The experimental results demonstrate that the process is the most efficient at 0.6 M acetic acid concentration, flow rate of 45 mL/min and current density of 4 mA/cm2. The mass balance data corresponding to the recycling of 10 kg/h waste CRT glass in the identified optimal operating conditions was used for the environmental assessment of the process. The General Effect Indices (GEIs), obtained through the Biwer Heinzle method for the input and output streams of the process, indicate that the developed recovery process not only achieve a complete recovery of lead but it is eco-friendly as well.

Photo-degradation of butyl parahydroxybenzoate by using TiO2-supported catalyst

2013 ◽  
Vol 67 (10) ◽  
pp. 2141-2147 ◽  
Author(s):  
Patrick Atheba ◽  
Patrick Drogui ◽  
Brahima Seyhi ◽  
Didier Robert
Keyword(s):  
Flow Rate ◽  
Photocatalytic Oxidation ◽  
Supported Catalyst ◽  
Operating Conditions ◽  
Treatment Efficiency ◽  
Optimal Operating ◽  
Photo Degradation ◽  
Photochemical Process ◽  
Recirculation Flow ◽  
High Treatment

The present work evaluates the potential of the photocatalysis (PC) process for the degradation of butylparaben (BPB). Relatively high treatment efficiency was achieved by comparison to photochemical process. Prior to photocatalytic degradation, adsorption (AD) of BPB occurred on the titanium dioxide (TiO2)-supported catalyst. AD was described by Langmuir isotherm (KL = 0.085 L g−1, qm = 4.77 mg g−1). The influence of angle of inclination of the reactor, pH, recirculation flow rate and initial concentration of BPB were investigated. The PC process applied under optimal operating conditions (recirculation flow rate of 0.15 L min−1, angle of inclination of 15°, pH = 7 and 5 mg L−1 of BPB) is able to oxidize 84.9–96.6% of BPB and to ensure around 38.7% of mineralization. The Langmuir–Hinshelwood kinetic model described well the photocatalytic oxidation of BPB (k = 7.02 mg L−1 h−1, K = 0.364 L mg−1).

Flow Features Analysis of Throttle Notches of Proportional Direct Valve

2011 ◽  
Vol 189-193 ◽  
pp. 2285-2288
Author(s):  
Wen Hua Jia ◽  
Chen Bo Yin ◽  
Guo Jin Jiang
Keyword(s):  
Fluid Flow ◽  
Dynamic Behavior ◽  
Flow Rate ◽  
Discharge Coefficient ◽  
3D Models ◽  
Operating Conditions ◽  
Flow Models ◽  
Flow Features ◽  
Rate Discharge ◽  
Spool Valve

Flow features, specially, flow rate, discharge coefficient and efflux angle under different operating conditions are numerically simulated, and the effects of shapes and the number of notches on them are analyzed. To simulate flow features, 3D models are developed as commercially available fluid flow models. Most construction machineries in different conditions require different actions. Thus, in order to be capable of different actions and exhibit good dynamic behavior, flow features should be achieved in designing an optimized proportional directional spool valve.

scholarly journals Experimental Investigation and Modeling of Inertance Tubes

2005 ◽  
Vol 127 (5) ◽  
pp. 1029-1037 ◽  
Author(s):  
L. O. Schunk ◽  
G. F. Nellis ◽  
J. M. Pfotenhauer
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Acoustic Power ◽  
Operating Conditions ◽  
Thermodynamic Efficiency ◽  
Pulse Tube ◽  
Design Charts ◽  
Wide Range ◽  
Pulse Tube Refrigerators

Growing interest in larger scale pulse tubes has focused attention on optimizing their thermodynamic efficiency. For Stirling-type pulse tubes, the performance is governed by the phase difference between the pressure and mass flow, a characteristic that can be conveniently adjusted through the use of inertance tubes. In this paper we present a model in which the inertance tube is divided into a large number of increments; each increment is represented by a resistance, compliance, and inertance. This model can include local variations along the inertance tube and is capable of predicting pressure, mass flow rate, and the phase between these quantities at any location in the inertance tube as well as in the attached reservoir. The model is verified through careful comparison with those quantities that can be easily and reliably measured; these include the pressure variations along the length of the inertance tube and the mass flow rate into the reservoir. These experimental quantities are shown to be in good agreement with the model’s predictions over a wide range of operating conditions. Design charts are subsequently generated using the model and are presented for various operating conditions in order to facilitate the design of inertance tubes for pulse tube refrigerators. These design charts enable the pulse tube designer to select an inertance tube geometry that achieves a desired phase shift for a given level of acoustic power.

The Role of Offshore Monitoring in an Effective Deepwater Riser Integrity Management Program

2007 ◽  
Author(s):  
Brittany Goldsmith ◽  
Elizabeth Foyt ◽  
Madhu Hariharan
Keyword(s):  
Failure Modes ◽  
Human Life ◽  
Management Program ◽  
Measured Data ◽  
Operating Conditions ◽  
Environmental Damage ◽  
Positioning Systems ◽  
Integrity Management ◽  
Deepwater Riser

As offshore field developments move into deeper water, one of the greatest challenges is in designing riser systems capable of overcoming the added risks of more severe environments, complicated well requirements and uncertainty of operating conditions. The failure of a primary riser component could lead to unacceptable consequences, including environmental damage, lost production and possible injury or loss of human life. Identification of the risks facing riser systems and management of these risks are essential to ensure that riser systems operate without failure. Operators have recognized the importance of installing instrumentation such as global positioning systems (GPS), vessel motion measurement packages, wind and wave sensors and Acoustic Doppler Current Profiler (ADCP) units to monitor vessel motions and environmental conditions. Additionally, high precision monitoring equipment has been developed for capturing riser response. Measured data from these instruments allow an operator to determine when the limits of acceptable response, predicted by analysis or determined by physical limitations of the riser components, have been exceeded. Regular processing of measured data through automated routines ensures that integrity can be quickly assessed. This is particularly important following extreme events, such as a hurricane or loop current. High and medium alert levels are set for each parameter, based on design analysis and operating data. Measured data is compared with these alert levels, and when an alert level is reached, further response evaluation or inspection of the components in question is recommended. This paper will describe the role of offshore monitoring in an integrity management program and discuss the development of alert levels based on potential failure modes of the riser systems. The paper will further demonstrate how this process is key for an effective integrity management program for deepwater riser systems.

scholarly journals Preparation and characterization of different geometrical shapes of multi-bore hollow fiber membranes and application in vacuum membrane distillation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Elham M. El-Zanati ◽  
Eman Farg ◽  
Esraa Taha ◽  
Ayman El-Guindi ◽  
Heba Abdallah
Keyword(s):  
Mechanical Properties ◽  
Flow Rate ◽  
Hollow Fiber ◽  
Amorphous Structure ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Hollow Fiber Membranes ◽  
Preparation Conditions ◽  
Geometrical Shapes ◽  
Fiber Membranes

Abstract Multi-bore hollow fiber membranes were prepared through phase inversion spinning process using new locally designed spinnerets of various geometrical shapes. The spun cylindrical-like, rectangular or ribbon-like, and triangular-like are prepared, dried, and characterized by scanning electronic microscope. Fibers of circular (seven, five, and four bores) shape, rectangular of five bores, and triangular of three bores were chosen to study the effect of both geometrical configuration and the number of bores on the amorphous structure and the mechanical properties of the membranes. Membrane geometry, surface amorphous, and bore arrangements are very sensitive to the operating conditions, especially the extrusion and drawing rates. Three polymeric blends of different compositions are used to prepare multi-bore hollow fiber membranes. This study revealed that the blend composition of PES 16%, PVP 2%, PEG 2%, diethylene glycol 2%, and NMP 78% gives excellent mechanical properties. Optimization of the preparation conditions also developed, where the dope flow rate, the bore flow rate, and the air gap were 1.14 cm3 s−1, 1.1 cm3 s−1, and 0 cm, respectively. Furthermore, this study proved that the circular arrangement has high mechanical strength. The prepared seven-MBHF membranes were applied in the membrane distillation process, a solution of 35 g/l NaCl was used to test the membrane performance, and the achieved flux and rejection were 28.32 L/m2 h and 98.9%, respectively. This performance demonstrated that the prepared membrane in this way is suitable to compete with conventional reverse osmosis technology that uses single track hollow fibers.

Experimental determination of IGV preswirl effect on impeller blade vibration in an unshrouded centrifugal compressor

2021 ◽  
pp. 095765092110247
Author(s):  
Xinwei Zhao ◽  
Hongkun Li ◽  
Shuhua Yang ◽  
Zhenfang Fan ◽  
Yang Wang
Keyword(s):  
Dynamic Stress ◽  
Operating Conditions ◽  
Large Shift ◽  
Blade Vibration ◽  
Impeller Blade ◽  
Inlet Flow ◽  
Vibration Data ◽  
Aerodynamic Loading ◽  
High Dynamic

The unshrouded impeller is widely used in industrial centrifugal compressors and normally operates at high tip speed and large volume flow. However, this type of impeller can be very sensitive to flow excitations such as IGV wake, and hence encounters the challenge of high dynamic stress. Due to the lack of experimental vibration data, this paper aims to enhance the understanding of the IGV preswirl effect. The real operating representative data from strain gauges is acquired during the experiment. The blade transient and quasi-steady response due to upstream IGV wake under different configurations are investigated and quantified. Results show that the blade response increases with larger positive regulation. And under specific operating conditions, the vibration of the blade is quite large, which is comparable with synchronize resonance. This increment is attributed to the aerodynamic loading change due to enhanced distortion of the inlet flow. Based on the current findings, accurate numerical prediction of the blade forced vibration for a large shift of inlet flow condition is also needed for more reliable operating of the impeller.

Assessment of the Loss Map of a Centrifugal Compressor’s External Volute

2020 ◽  
Author(s):  
Thomas Ceyrowsky ◽  
Andre Hildebrandt ◽  
Martin Heinrich ◽  
Rüdiger Schwarze
Keyword(s):  
Mach Number ◽  
Flow Rate ◽  
Numerical Approach ◽  
Operating Conditions ◽  
Circumferential Velocity ◽  
Flow Angle ◽  
Absolute Flow ◽  
Highly Sensitive ◽  
Geometrical Features ◽  
Comparison With Experimental Data

Abstract A volute’s loss coefficient is highly sensitive to Mach number, circumferential velocity and flow rate at volute inlet. In case of a backswept impeller, these parameters are coupled to each other. An increased flowrate leads to a steeper absolute flow angle at impeller exit and hence to a decrease of circumferential velocity. The absolute Mach number is also altered. Therefore, in order to investigate the effects of flowrate and flow angle separately, one would have to vary the diffuser width together with the flowrate, keeping the flow angle constant. This corresponds to coupling the volute with aerodynamically similar impellers, designed for higher and lower flowrates. Since this is elaborate, there is no adequate study available in open literature, assessing a volute’s global loss map. In this work, a new numerical approach for the prediction of a volute’s representative loss map is presented: The volute is calculated by means of steady CFD as a standalone component. The inlet boundary conditions are carefully selected by means of 1D and applied together with different diffuser widths. This allows for separate investigation of the impacts of flow angle, flow rate and Mach number. Validation against full stage CFD confirms the applicability of the standalone model. The results exhibit that minimum losses do not necessarily occur at the theoretical matching point but either when the volute is smaller or bigger, depending on the inlet flow angle. Investigations of the loss mechanisms at different operating conditions provide useful guidelines for volute design. Finally, the validity of these study’s findings for volutes with different geometrical features is examined by comparison with experimental data as well as with fullstage CFD.

Influence of the Variation of Plasma Torch Parameters on Particle Melting and Solidification

1997 ◽  
Author(s):  
M. Vardelle ◽  
P. Fauchais ◽  
A. Vardelle ◽  
A.C. Léger
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Gas Flow ◽  
Operating Conditions ◽  
Characteristic Parameters ◽  
Powder Mass ◽  
Arc Current ◽  
Plasma Sprayed ◽  
Carrier Gas Flow ◽  
Melting And Solidification

Abstract A study of the flattening and cooling of particles plasma-sprayed on a substrate is presented. The characteristic parameters of the splats are linked to the parameters of the impacting particles by using an experimental device consisting of a phase Doppler particle analyzer and a high-speed pyrometer. However, during the long experiments required to get reliable correlations, it was observed that variations in plasma spray operating conditions may alter the particles behavior in the plasma jet. Therefore, a simple and easy-to-use system was developed to control in real time the spray jet. In this paper, the effect of carrier gas flow rate, arc current and powder mass flow rate is investigated. The results on zirconia and alumina powders show the capability of the technique to sense the particle spray position and width.

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