A novel vibration system based on instantaneous motion centre for high accuracy dynamic balancing measurement of outboard rotor

2009 ◽  
Vol 223 (2) ◽  
pp. 387-395 ◽  
Author(s):  
Q Peng ◽  
C Ping
Keyword(s):  
Coupling Effect ◽  
Separation Performance ◽  
Vibration System ◽  
Beam Structure ◽  
Dynamic Balancing ◽  
Term Operation ◽  
Force Coupling ◽  
In Series ◽  
Separation Performances ◽  
Balancing Efficiency

To overcome the disadvantages of the traditional vibration system used in a horizontal dynamic balancing machine, based on the principle of the instantaneous motion centre in theoretical mechanics, a novel two-degree-of-freedom vibration system comprising two non-parallel four-bar linkages in series is designed to improve the plane separation effect and minimum achievable residual unbalance for dynamic balancing measurement of an outboard rotor. The structure characteristics and unbalancing response of this vibration system are analysed in depth. The plane separation equations are derived. Theoretical analyses show that this vibration system integrates the advantages of both the overhanging beam structure and simple-supported beam structure, and its vibration centre keeps at the instantaneous motion centres, with the result that the balancing efficiency and plane separation performances are improved. Moreover, to improve the sensitivity of the vibration system, the distance between measuring planes is increased by adjusting the angles of two four-bar linkages. The transducers are installed on the same measuring plane; thus, the performance difference in transducers caused by environment fluctuation is reduced and the force coupling effect is eliminated. The result for this vibration system in long-term operation is a more accurate measurement with a lower requirement for a second correction run. The final experimental results validate the superiority of this vibration system in plane separation performance, minimum achievable residual unbalance, and repeatability.

Numerical Simulations of Capillary Electrokinetic Pinched Injection Separation Flows in Microchannels

2004 ◽  
Author(s):  
Bakhtier Farouk ◽  
Fang Yan
Keyword(s):  
Electric Field ◽  
Numerical Simulations ◽  
Separation Performance ◽  
Species Concentration ◽  
Separation Channel ◽  
Electrokinetic Flow ◽  
Step Flow ◽  
Optimal Separation ◽  
Separation Flows ◽  
Separation Performances

Numerical simulations were performed to study the capillary electrokinetic flow in microchannels. A sample stream consisting of three different species is focused during the loading step and driven into a separation channel during the dispensing step. Flow fields and species distributions are simulated for both the loading and the dispensing steps in a two dimensional cross channel device. The evolution of each sample species concentration at the end of the separation channel is predicted. The separation resolution is defined from the sample species concentration band retention time and band width. Different separation performances can be obtained by manipulating the electric field strengths. A series of simulations for different electric field distributions and field magnitudes in the channel are presented. The goal of these simulations is to identify the parameters providing optimal separation performance. The effect of both loading and dispensing schemes on species concentration and separation resolution is presented.

Polyion Complex Chitosan Membrane Consisting of Sodium Alginate/Chitosan for the Pervaporation Separation of Methanol/Methyl tert-butyl Ether Mixtures

2013 ◽  
Vol 66 (1) ◽  
Author(s):  
M. G. Mohd Nawawi ◽  
Zafifah Zamrud
Keyword(s):  
Sodium Alginate ◽  
Composite Membranes ◽  
Methyl Tert Butyl Ether ◽  
Separation Performance ◽  
Butyl Ether ◽  
Polyion Complex ◽  
Tert Butyl ◽  
Swelling Characteristics ◽  
Separation Performances ◽  
Feed Temperature

The polyion complex (PIC) composite membranes consisting of chitosan (CS) and sodium alginate (SA) were prepared for the separation of methanol/methyl tert-butyl ether (MTBE) mixtures via pervaporation process. Membrane morphologies showed that CS and SA were homogenously intermixed for all blended ratio tested. Swelling characteristics observed all membranes were readily swelled in the solution mixtures containing more methanols. Separation performance of the membranes via pervaporation was performed on the effect of SA composition in the membrane blend, effect of MTBE concentration in the feed and effect of feed temperature. Overall separation performances showed that the membranes were highly permselective towards methanol due to the affinity and polarity for all the studied parameters. 

Vibration Localization in a Fluid-Loaded Rectangular Plate with Rib Irregularity

2012 ◽  
Vol 226-228 ◽  
pp. 191-194
Author(s):  
Hao Hao Hu ◽  
De Jiang Shang
Keyword(s):  
Coupling Effect ◽  
Coupled System ◽  
Expansion Method ◽  
Heavy Fluid ◽  
Range Interaction ◽  
Modal Expansion ◽  
Vibration Localization ◽  
Modal Expansion Method ◽  
Force Coupling ◽  
Long Range Interaction

This paper studies the vibration localization of fluid-loaded irregularly ribbed plate analytically. The modal expansion method was adopted to solve the multi-coupled system, the ribs were considered as Timoshenko beams attached to the plate. The localization mechanism was investigated by comparing different coupling effect at the plate-beam interface, it was found the ribs space irregularity only localize the modes associated with the shear force coupling. Both the light and heavy fluid loading pressure were concerned by Rayleigh integral , the study showed that obvious vibration localization phenomenon can be achieved by the ribs space irregularity, and the localization effect was weakened by the long range interaction through the heavy fluid, although the response amplitude of the modes decreased obviously. The investigation may be quite significant for vibration confinement and noise control in engineering.

Study on the Two-Side Direction Burr in Grinding-Hardening Machine Based on Orthogonal Experimental Method

2012 ◽  
Vol 217-219 ◽  
pp. 1869-1873 ◽  
Author(s):  
Ju Dong Liu ◽  
Wei Yuan ◽  
Jin Kui Xiong ◽  
Zhi Long Xu ◽  
Song Wei Huang
Keyword(s):  
Coupling Effect ◽  
Orthogonal Experiment ◽  
Depth Of Cut ◽  
Actual Application ◽  
Grinding Method ◽  
Force Coupling ◽  
Grinding Hardening ◽  
Table Speed ◽  
Significant Factors

Based on the orthogonal experiment, this paper studied the influences of depth of cut ap, table speed vw and grinding method gm on the two-side direction burr in grinding-hardening machine. The results show that, with thermal-force coupling effect induced in the grinding-hardening machine, the metal in the workpiece’s surface flowed to two-side direction of the workpiece that without any constraint and leaded to the burr’s formation. The depth of cut ap and grinding method gm are significant factors that affected the size of two-side direction burr, and the significant order are as follows: depth of cut ap> grinding method gm > table speed vw>interaction av. With the increasing of depth of cut ap or the grinding trip, the max size of the two-side direction burr increased gradually; and with the raising of table speed vw, the max size decreased firstly and then increased. In actual application, it should adopted the grinding parameters ap＝0.2mm，vw＝0.6m/min and up-down grinding to improve the quality of grinding-hardening and reduce the size of the burr.

Research on a Novel Vibration System for Dynamic Balancing Measurement Based on Flexure Hinge Mechanism

2008 ◽  
Vol 381-382 ◽  
pp. 121-124
Author(s):  
D. Zhao ◽  
P. Qin ◽  
Ping Cai
Keyword(s):  
Optimal Design ◽  
Theoretical Analysis ◽  
Natural Frequencies ◽  
Flexure Hinge ◽  
Vibration System ◽  
Equivalent Stiffness ◽  
Dynamic Balancing ◽  
Flexure Hinges ◽  
Kinetics Modeling ◽  
Simulation Results

A novel vibration system for dynamic balancing measurement is presented based on flexure hinges mechanism. A kinetics modeling for this novel vibration system is established, and its equivalent stiffness and natural frequencies are analyzed in depth. Finally the obtained simulation results by ANSYS FEM validate the correction of the theoretical analysis and provide advantageous conclusions for optimal design of vibration system.

scholarly journals Synthesis, Characterization, and CO2/N2 Separation Performance of POEM-g-PAcAm Comb Copolymer Membranes

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 177
Author(s):  
Byeong Ju Park ◽  
Na Un Kim ◽  
Chang Soo Lee ◽  
Jong Hak Kim
Keyword(s):  
Spectroscopic Studies ◽  
Amorphous Structure ◽  
Proton Nuclear Magnetic Resonance ◽  
Separation Performance ◽  
Scanning Calorimetry ◽  
Free Standing ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Comb Copolymer ◽  
Separation Performances

Alcohol-soluble comb copolymers were synthesized from rubbery poly(oxyethylene methacrylate) (POEM) and glassy polyacrylamide (PAcAm) via economical and facile free-radical polymerization. The synthesis of comb copolymers was confirmed by Fourier-transform infrared and proton nuclear magnetic resonance spectroscopic studies. The bicontinuous microphase-separated morphology and amorphous structure of comb copolymers were confirmed by wide-angle X-ray scattering, differential scanning calorimetry, and transmission electron microscopy. With increasing POEM content in the comb copolymer, both CO2 permeability and CO2/N2 selectivity gradually increased. A mechanically strong free-standing membrane was obtained at a POEM:PAcAm ratio of 70:30 wt%, in which the CO2 permeability and CO2/N2 selectivity reached 261.7 Barrer (1 Barrer = 10−10 cm3 (STP) cm cm−2 s−1 cmHg−1) and 44, respectively. These values are greater than those of commercially available Pebax and among the highest separation performances reported previously for alcohol-soluble, all-polymeric membranes without porous additives. The high performances were attributed to an effective CO2-philic pathway for the ethylene oxide group in the rubbery POEM segments and prevention of the N2 permeability by glassy PAcAm chains.

scholarly journals Nano-porous Zeolite and MOF Filled Mixed Matrix Membranes for Gas Separation

2021 ◽  
Vol 333 ◽  
pp. 04008
Author(s):  
Yongsheng Liu ◽  
Kyosuke Takata ◽  
Yu Mukai ◽  
Hidetoshi Kita ◽  
Kazuhiro Tanaka
Keyword(s):  
Gas Separation ◽  
Maxwell Model ◽  
Polymer Membrane ◽  
Mixed Matrix Membranes ◽  
Separation Performance ◽  
Mixed Matrix ◽  
Trade Off ◽  
Ideal Selectivity ◽  
Separation Performances ◽  
Matrix Membranes

The commercial SAPO-34 zeolite with 0.38 nm pore size and ZIF-8 particles with 0.34 nm aperture size were separately dispersed into different polymer matrix, to prepare the mixed matrix membranes (MMMs) for gas separation. The dispersed situation of the SAPO-34 and ZIF-8 particles in matrix and the influence of the fillers on the separation performance of the membrane had been investigated in this study. The as-synthesized MMMs showed a better trade-off between permeability and selectivity than the pure polymer membrane and the performance could exceed or close to the upper bound line of polymer membrane for CO2 and CH4 separation. The CO2 permeability and CO2/CH4 ideal selectivity of the 6FDA-mDAT MMM containing 40 wt% SAPO-34 zeolite was 190 barrer and ca. 60, respectively. The 6FDA-TrMPD based MMMs containing 20 wt% ZIF-8 provided a permeability of C3H6 and an ideal selectivity of C3H6/C3H8 at 24 barrer and ca. 17, respectively. These separation performances were in a suitable agreement of the theoretical value from Maxwell model.

Changes in measured biodegradation kinetics during the long-term operation of completely mixed activated sludge (CMAS) bioreactors

1996 ◽  
Vol 34 (5-6) ◽  
pp. 35-42 ◽  
Author(s):  
Timothy G. Ellis ◽  
Barth F. Smets ◽  
Benjamin S. Magbanua ◽  
C. P. Leslie Grady
Keyword(s):  
Activated Sludge ◽  
Kinetic Parameters ◽  
Plug Flow ◽  
Biodegradation Kinetics ◽  
Monod Kinetics ◽  
Term Operation ◽  
In Series ◽  
Parameter Values ◽  
Ks Values

Two completely mixed activated sludge (CMAS) bioreactors, one with an aerobic selector and one without, were operated for approximately twelve and sixteen months, respectively. Extant biodegradation kinetics for several compounds were periodically tested using a batch respirometric procedure. Kinetic parameters from the CMAS unit without a selector showed considerable variability (standard deviation of ± 50%) even though it was operated at steady state (i.e. constant HRT, SRT, organic loading, etc.) for the duration of the study. At first, there was a large discrepancy between the kinetic parameters of the two bioreactors. Phenol and 4-chlorophenol were biodegraded according to Monod kinetics in the selector system and Andrews (inhibitory) kinetics in the non-selector system, and the μ^ and KS values were significantly greater in the selector system. The kinetic parameter values of the two systems converged, however, when the xenobiotic compounds were no longer fed to the selector in that system but were fed to the main bioreactor. After this switch, phenol and 4-chlorophenol followed inhibitory kinetics in both systems. The lack of inhibition when phenol and 4-chlorophenol were fed to the selector suggests that, contrary to conventional wisdom, bioreactors which have a concentration gradient (e.g. plug flow, sequencing batch, and tanks in series bioreactors) may be more resistant to inhibition.

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