Optimizing on hydrostatic structural parameters for regulatable dry gas seal based on central composite design test

2016 ◽  
Vol 68 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Zhaoxu Jin ◽  
Shuangxi Li ◽  
Jining Cai ◽  
qiuxiang zhang
Keyword(s):  
Film Thickness ◽  
Central Composite Design ◽  
Structural Parameters ◽  
Force Balance ◽  
Theoretical Research ◽  
Analysis Method ◽  
Content Type ◽  
Dry Gas Seal ◽  
Actual Working ◽  
Central Composite

Purpose – This paper aims to introduce a new type of analysis method to seek the actual working performance of the regulatable dry gas seal, including equilibrium film thickness, stiffness-leakage ratio and so on. Additionally, a parametric optimization of the hydrostatic structure is completed for this kind of seal. Design/methodology/approach – From the point of axial force balance based on gas lubrication theory, a new analysis method, the Gas Film Divided Method, has been introduced. A four-factor and three-level hydrostatic structural parameters test scheme is designed by means of Central Composite Design test and then the hydrostatic structural parameters of regulatable dry gas seal were optimized. Three types of regulatable dry gas seal have been designed and manufactured to verify the theoretical analysis by measuring the equilibrium film thickness and inward leakage. Findings – The results indicate that the numerical values of the Gas Film Divided (GFD) method agree well with the experimental ones. Test proves that the Central Composite Design test could achieve optimized hydrostatic structural parameters of regulatable dry gas seal effectively. Research limitations/implications – For validating the correctness of the GFD method, an experiment study of the regulatable dry gas seal is being carried out where atmosphere is selected as the lubricant for the sake of safety. Soon after, the author will discuss the application in the new paper. Originality/value – The introduction of the GFD method proffers important insights to seek the performances of regulatable dry gas seal under the actual working conditions. The detailed optimal values of the hydrostatic structural parameters were given by the theoretical research which may be helpful for the design of regulatable dry gas seal.

The influence of 3-DOF film thickness disturbance on transient performance of typical spiral groove dry gas seals

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuan Chen ◽  
Hao Shang ◽  
Xiaolu Li ◽  
Yuntang Li ◽  
Bingqing Wang ◽  
...  
Keyword(s):  
Film Thickness ◽  
Degrees Of Freedom ◽  
Thickness Distribution ◽  
Transient Performance ◽  
Spiral Groove ◽  
Double Row ◽  
Content Type ◽  
Dry Gas Seal ◽  
Sealing Performance ◽  
Gas Seals

Purpose The purpose of this paper is to investigate the influence rule and mechanism of three degrees of freedom film thickness disturbance on the transient performance of spiral groove, upstream pumping spiral groove dry gas seal (UP-SDGS) and double-row spiral groove dry gas seal (DR-SDGS). Design/methodology/approach The transient performance of spiral groove, UP-SDGS and DR-SDGS are obtained by solving the transient Reynolds equation under different axial and angular disturbance coefficients. The transient and steady performance of the above-mentioned DGSs are compared and analyzed. Findings The film thickness disturbance has a remarkable impact on the sealing performance of DGS with different structures and the calculation deviations of the leakage rate of the UP-DGS will increase significantly if the film thickness disturbance is ignored. The axial and angular disturbance jointly affect the film thickness distribution of DGS, but there is no significant interaction between them on the transient sealing performance. Originality/value The influence mechanism of axial disturbance and angular disturbance on the transient performance of typical SDGSs behavior has been explained by theory. Considering small and large disturbance, the interaction between axial disturbance and angular disturbance on the transient performance have been studied.

Lubrication regime analysis for spherical pump

2018 ◽  
Vol 70 (8) ◽  
pp. 1437-1446 ◽  
Author(s):  
Dong Guan ◽  
Harry H. Hilton ◽  
Zhengwei Yang ◽  
Li Jing ◽  
Kuan Lu
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Structural Parameters ◽  
Equivalent Model ◽  
Radial Clearance ◽  
Content Type ◽  
Factors Affecting ◽  
Operational Conditions ◽  
Intellectual Content ◽  
Lubrication Regime

Purpose This paper aims to investigate the lubrication regime in spherical pump, especially under different structural parameters and operational conditions. Design/methodology/approach A ball-on-plane configuration is adopted to represent the contact model between spherical piston and cylinder cover. The governing equations, which include the Reynolds and elasticity equations, are solved and validated by Jin–Dowson model. Both minimum film thickness and lambda ratio (ratio of minimum fluid film thickness to combined surface roughness of the piston and cylinder cover) of the equivalent model are obtained using an established model. Findings The results indicate that piston diameter and radial clearance are the two main factors affecting the pump lubrication regime. Other related parameters such as rotation speed of the piston, load, viscosity of working medium, material matching and surface roughness of piston and cylinder cover also have different impacts on the lubrication regime of the spherical pump. Originality/value These results emphasize the importance of the design and manufacturing parameters on the tribological performance of spherical pumps and these are also helpful in improving the spherical pump lubrication regime and enlarging its life cycle. This is to certify that to the best of the authors’ knowledge, the content of this manuscript is their own work. This manuscript has only been submitted to this journal and never been published elsewhere. The authors certify that the intellectual content of this manuscript is the product of their own work and that all the assistance received in preparing this manuscript and sources has been acknowledged.

Thermal effect on stability and minimum oil film thickness of a deep/shallow pockets conical bearing

2020 ◽  
Vol 72 (10) ◽  
pp. 1251-1257
Author(s):  
Ningning Wu ◽  
Hong Guo ◽  
Shuai Yang ◽  
Shaolin Zhang
Keyword(s):  
Film Thickness ◽  
Thermal Effect ◽  
Peer Review ◽  
Critical Mass ◽  
Rotor System ◽  
Force Balance ◽  
Dynamic Coefficient ◽  
Content Type ◽  
Oil Film ◽  
Hybrid Bearing

Purpose This paper aims to study the influence of thermal effect on the performance for a high-speed conical hybrid bearing including stability and minimum oil film thickness. Design/methodology/approach A thermal hydrodynamic (THD) model and dynamic model of single mass rigid rotor system were established by taking conical hybrid bearing with shallow and deep pockets as the research object, dynamic coefficient and stability parameters of bearing-rotor system were obtained by using finite element method (FEM) and finite difference method (FDM) to solve computational models of Reynolds equation, energy equation and viscosity-temperature equation. Minimum oil film thickness was obtained based on bearing force balance. Dynamic coefficient was compared with previous findings. Findings After considering thermal effect, the dimensionless critical mass decreases, a significant decrease in the instability speed, and the stability of the system decreases greatly; the minimum oil film thickness decreases because of thermal effect. Originality/value The thermal effect is combined with dynamic characteristics to analyze stability of the rotor system for a conical hybrid bearing. Influence of thermal effect on minimum oil film thickness is studied. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0542/

Prediction of wear resistance model for magnesium metal composite by response surface methodology using central composite design

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Prem Sagar ◽  
Amit Handa
Keyword(s):  
Wear Resistance ◽  
Response Surface Methodology ◽  
Central Composite Design ◽  
Process Parameters ◽  
Wear Mechanism ◽  
Metal Composite ◽  
Magnesium Metal ◽  
Content Type ◽  
Tool Rotation ◽  
Central Composite

Purpose In recent days, friction stir processing (FSP) has emerged as a pioneering approach for the manufacture of composites with enhanced mechanical and tribological properties. The present study aims to examine the impact of process parameters such as tool rotation speed and number of FSP pass on the AZ61A/TiC magnesium metal composite for responses such as hardness and wear resistance. Design/methodology/approach To minimize number of experimental runs, design of experiment was configured according to the response surface methodology using central composite design. Analysis of variance has been conducted to develop mathematical and empirical model for studying relationship between tool rotation and number of pass for responses such as microhardness and wear resistance. Microhardness was checked on vickers microhardness testing machine, and tribological behavior were examined on pin-on-disc using tribotester. Wear morphology was analyzed via scanning electron microscopy. Findings The responses were predicted using validated mathematical model, and contour plots were generated to study the interaction and influence of process parameters. Wear observations suggest that for the base magnesium alloy adhesive wear mechanism was dominating and for the developed nanocomposites, abrasive wear mechanism is a prominent factor. It was also observed that both the selected parameters significantly influenced the responses. Originality/value To the best of the authors’ knowledge, no prior work has been conducted with this material and preparation of composites with TiC nanoparticles. Furthermore, no mathematical models have been developed to predict the response values.

Polyurethane based finishing of cotton fabric for imparting multifunctional properties by using central composite design

2016 ◽  
Vol 45 (6) ◽  
pp. 444-449
Author(s):  
Zulfiqar Ali Raza ◽  
Aisha Rehman ◽  
Rashid Masood
Keyword(s):  
Tensile Strength ◽  
Central Composite Design ◽  
Strength Loss ◽  
Content Type ◽  
Moisture Management ◽  
Durable Press ◽  
Management Capability ◽  
Parabolic Relationship ◽  
Recovery Angle ◽  
Central Composite

Purpose The purpose of this study was to overcome discomfort associated with it, a resin finish was applied in conjunction with hydrophilic polyurethane. Design/methodology/approach The process variables included concentrations of polyurethane and resin finishes, and pH under central composite design (CCD). The fabric specimens were assessed for crease recovery angle (CRA), tensile strength and moisture management properties. Findings Some models were developed for prediction of CRA and overall moisture management capability (OMMC) of treated fabric. It was observed that polyurethane concentration showed a parabolic relationship with CRA and a direct relationship with OMMC, whereas resin concentration showed a parabolic relationship with CRA and an inverse relationship with OMMC. Increase in pH from acidic to alkaline resulted in a decrease in CRA but an increase in OMMC. The untreated specimen had the highest tensile strength, whereas the specimen treated with polyurethane showed the least tensile strength loss, and the one treated with resin showed the highest loss in tensile strength. Practical implications As the polyurethane-based finish is soft and hydrophilic, so it was expected that it would overcome the uncomfortable feature of durable press finish, and with its flexibility, the strength losses might reduce. Originality/value This is the first report about the investigation of effects of increasing flexibility of the cross-link by incorporating polyurethane compounds into a typical dimethylol dihydroxy ethylene urea durable press resin formulation.

Development and optimization of solid lipid nanoparticles of amikacin by central composite design

2009 ◽  
Vol 00 (00) ◽  
pp. 090721051030036-8
Author(s):  
Jaleh Varshosaz ◽  
Solmaz Ghaffari ◽  
Mohammad Reza Khoshayand ◽  
Fatemeh Atyabi ◽  
Shirzad Azarmi ◽  
...  
Keyword(s):  
Central Composite Design ◽  
Solid Lipid Nanoparticles ◽  
Lipid Nanoparticles ◽  
Solid Lipid ◽  
Central Composite

Formulation Design and Optimization of Repaglinide Solid Dispersions by Central Composite Design

2018 ◽  
Vol 11 (6) ◽  
pp. 4337-4348
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Srinivas I
Keyword(s):  
Central Composite Design ◽  
Dissolution Rate ◽  
Solid Dispersion ◽  
Solid Dispersions ◽  
Solvent Evaporation ◽  
Release Mechanism ◽  
Solvent Evaporation Method ◽  
Onset Of Action ◽  
Evaporation Method ◽  
Central Composite

Repaglinide is a pharmaceutical drug used for the treatment of type II diabetes mellitus, it is characterized with poor solubility which limits its absorption and dissolution rate and delays onset of action. In the present study, immediate release solid dispersion of repaglinide was formulated by solvent evaporation technique. Repaglinide solid dispersions were prepared using PEG 8000, Pluronic F 127 and Gelucire 44/14 by solvent evaporation method. A 3-factor, 3-level central composite design employed to study the effect of each independent variable on dependent variables. FTIR studies revealed that no drug excipient interaction takes place. From powder X-ray diffraction (p-XRD) and by scanning electron microscopy (SEM) studies it was evident that polymorphic form of repaglinide has been converted into an amorphous form from crystalline within the solid dispersion formulation. The correlation coefficient showed that the release profile followed Higuchi model anomalous behavior and hence release mechanism was indicative of diffusion. The obtained results suggested that developed solid dispersion by solvent evaporation method might be an efficacious approach for enhancing the solubility and dissolution rate of repaglinide.

Optimization of Pan Coating Process for Increased Efficiency of Controlled-Release Urea Fertilizer

2021 ◽  
Vol 57 (4) ◽  
pp. 333-342
Author(s):  
Trung Huu Nguyen ◽  
Tran Nguyen Minh An ◽  
Mahboob Alam ◽  
Duc Hoai Tran ◽  
Nghi Tran ◽  
...  
Keyword(s):  
Controlled Release ◽  
Layer Thickness ◽  
Release Time ◽  
Coating Process ◽  
Analysis Method ◽  
Sauter Mean Diameter ◽  
Urea Fertilizer ◽  
The Relationship ◽  
Central Composite ◽  
Controlled Release Urea

The goal of the research is to develop an experimental mathematical model of pan coating process effect on the biodegradable polymer and to determine optimal process parameters. The polymer solution was conducted with phosphated di-starch phosphate, polyvinyl alcohol, and polyacrylic acid and performed as material coating for the controlled-release urea fertilizer. The image analysis method has been used to determine the particle size distribution, Sauter mean diameter of the particle and layer thickness that is novel. The central composite rotatable design has been selected to determine the regression models of the process, which described the relationship between two objective variables as layer thickness, release time with angle of pan, spray flow, and coating time. The statistical analysis results indicate the fitness of model.

Sign in / Sign up

Export Citation Format

Share Document