Research and Development of Minitype Twin-Bladed Air Turbine

2009 ◽  
Author(s):  
Shih-Chun Wang ◽  
Kuang-Yuh Huang
Keyword(s):  
High Speed ◽  
Turbine Blades ◽  
Design Parameters ◽  
Operational Parameters ◽  
Micro Fabrication ◽  
Air Turbine ◽  
Speed Performance ◽  
Operational Energy ◽  
And Performance

In order to improve the machining efficiency of ultra-precision and micro fabrication technology, a high speed spindle is essential for the minitype tools widely applied in systems such as PCB drilling machines, micro fabrication machines, dental handpieces, etc. To realize the high speed performance, the air driven turbine is verified to be more feasible than the electromagnetic actuator. Furthermore, the operational efficiency and quality of the high speed spindle are significantly influenced by the turbine blades and the bearings respectively. Through detailed configurational studies and performance analyses on diverse minitype turbine blades, we have derived the efficiency- and quality-influential parameters. And based on optimization results, we have developed a novel type of twin bladed air turbine (TB-air turbine), which consists of two parallel blades with an angular offset. The offseted twin blades can efficiently and smoothly transform pneumatic energy into rotational energy. Therefore, steady driving force and less dynamic unbalance are able to be easily achieved for reducing nervous disturbances such as vibration, noise, and wear. By applying finite element analytical method, the operational performances and quality of the new developed twin bladed air turbine such as rotational speed, torque, vibration and noise were analyzed for comprehending influences of the design parameters and the operational parameters. While the inlet angle, the blade shape and its geometric parameters are the dominant design parameters; the inlet pressure and mass flow rate, and the outlet pressure are the main operational parameters. Through the turbine blades, the pneumatic energy will be transformed into operational energy in form of the flow field and the pressure distribution and the energy loss in form of turbulence. Also by integrating knowledge of production technology, a neat design of the turbine blades suitable for automatic manufacturing process is developed. And furthermore, through an elaborate layout of the flow guiding, a minimum rotational runout can be effectively achieved without any complicate and costly dynamic balancing process. Consequently, it has significantly depressed the stream noise and raised the operation lifetime of bearings. According to our experimental verification, the vibration and the stream noise of our TB-air turbines are 60% and 50% lower than traditional counterparts respectively. Our developed minitype spindle with novel TB-air turbine can efficiently realize high speed rotation with high torque, less vibration and less noise.

scholarly journals Surface Quality Assessment after Milling AZ91D Magnesium Alloy Using PCD Tool

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 617 ◽  
Author(s):  
Ireneusz Zagórski ◽  
Jarosław Korpysa
Keyword(s):  
Surface Roughness ◽  
Magnesium Alloy ◽  
High Speed ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Roughness Parameters ◽  
Operational Parameters

Surface roughness is among the key indicators describing the quality of machined surfaces. Although it is an aggregate of several factors, the condition of the surface is largely determined by the type of tool and the operational parameters of machining. This study sought to examine the effect that particular machining parameters have on the quality of the surface. The investigated operation was the high-speed dry milling of a magnesium alloy with a polycrystalline diamond (PCD) cutting tool dedicated for light metal applications. Magnesium alloys have low density, and thus are commonly used in the aerospace or automotive industries. The state of the Mg surfaces was assessed using the 2D surface roughness parameters, measured on the lateral and the end face of the specimens, and the end-face 3D area roughness parameters. The description of the surfaces was complemented with the surface topography maps and the Abbott–Firestone curves of the specimens. Most 2D roughness parameters were to a limited extent affected by the changes in the cutting speed and the axial depth of cut, therefore, the results from the measurements were subjected to statistical analysis. From the data comparison, it emerged that PCD-tipped tools are resilient to changes in the cutting parameters and produce a high-quality surface finish.

Design Parameter Sensitivity for a Mountain Bike Rear Shock

2006 ◽  
Author(s):  
Robin C. Redfield
Keyword(s):  
High Speed ◽  
Current Trend ◽  
Graph Model ◽  
Bond Graph ◽  
Design Parameters ◽  
Mountain Biking ◽  
Mountain Bike ◽  
Suspension Systems ◽  
Experimental Response ◽  
And Performance

As the sport of mountain biking matures, equipment continually evolves to afford better biking performance, enjoyment, and safety. In the arena of suspension systems, mountain bikes have moved from rigid suspensions with large, knobby tires to front fork suspensions, and finally full suspensions. Suspensions have gone from elastomeric compliance to air and coil springs with adjustable travel. Damping has progressed from fixed to adjustable rebound, compression, and lockout. The current trend is to add force or frequency dependent damping to minimize response of a suspension from pedal input. A bond graph model of a mountain bike rear shock is developed incorporating adjustable rebound and low-speed compression, high-speed compression, and rider controlled, compression damping initiation. An air shock with a nitrogen charge is modeled with velocity across the shock as input. The dynamic equations that come from the bond graph are simulated to predict key forces, pressures, and flow-rates. Experimental response (forces, displacements, and velocities) of the modeled shock is acquired subject to periodic velocity inputs. The experimental response is used to tune the design parameters of the model and for validation. A sensitivity analysis is then undertaken to determine how significant key design parameters are to the performance of the shock. Once validated, the model is used to better understand the physics and performance of the mountain bike shock and to relate performance to the requirements of expert mountain bikers.

An Analysis of Rigid Sidewall Surface Effect Craft for High-Speed Personnel Transportation

1970 ◽  
Vol 7 (01) ◽  
pp. 55-68
Author(s):  
Eugene R. Miller
Keyword(s):  
High Speed ◽  
Surface Effect ◽  
Transportation Cost ◽  
Total Power ◽  
Design Parameters ◽  
Economic Criterion ◽  
Calm Water ◽  
And Performance ◽  
Commercial Applications ◽  
Sidewall Surface

A number of commercial applications have been proposed for rigid sidewall surface effect craft. The transport of crews to offshore operations is an application which is well-suited to the immediate use of moderately sized craft of this type. Because the crews are paid while they are in transit, high speeds are required to minimize the total transportation costs. The characteristics and performance of rigid sidewall surface effect craft suitable for crew transport operations are developed. The major design parameters studied include pay-load, total power, and machinery type. Performance estimates are made for operations in both calm water and waves. An economic model is developed to simulate crewboat operations. Cost estimates are based on current technology and price levels. The total unit transportation cost is used as the economic criterion in the determination of the relative merit of various craft. For the purpose of comparison the characteristics and costs of planing hull crewboats for the same mission are developed. It is concluded that rigid sidewall surface effect craft have the potential of being economically superior to planing boats for crew transport operations.

Effectiveness Observed by Passengers Taking the Taiwan High Speed Railway Service: Especially their Observation of Overall Quality and Satisfaction

2012 ◽  
Vol 482-484 ◽  
pp. 555-558
Author(s):  
Chin Hsin Chiu ◽  
Hsuan Yi Chen ◽  
Chii Hwa Liang ◽  
Li Hsing Ho
Keyword(s):  
High Speed ◽  
Quality Service ◽  
High Speed Railway ◽  
Train Station ◽  
The Third ◽  
Quality Dimensions ◽  
Service Quality Dimensions ◽  
And Performance ◽  
High Quality Service

Abstract. This paper is regarding research concerning Taiwan’s High Speed Railway (THSR) service; its quality and performance. Most of the passengers preferred this transportation when compared with other trains because it is clean, convenient, comfortable, and saves time, while offering high quality service. The paper has 5 service quality dimensions. It includes 28 items in the form of a questionnaire for passengers which focused on the Hsichu station. The first dimension concerns boarding the train; the second is inside the train station; the third is on the platform; the fourth is riding the train, and the last one is leaving the THSR station. The analysis shows the Strengths, Weaknesses, Opportunities, Threats (SWOT) and the Importance Performance Analysis (IPA). The research is in regard to passenger’s satisfaction with the quality of service and customer satisfaction.

Dental Air Turbine Performance Study Using CFD and Experimental Approach

2010 ◽  
Author(s):  
Hsiao-Wei D. Chiang ◽  
Chih-Neng Hsu ◽  
Ya-Yi Chang ◽  
Shun-Yao Chuang
Keyword(s):  
Turbine Blade ◽  
Turbine Blades ◽  
Flow Channel ◽  
Design Parameters ◽  
Major Influence ◽  
Power Performance ◽  
Performance Study ◽  
Rotating Speed ◽  
Air Turbine ◽  
Cfd Analyses

Dental air turbine handpieces have been widely used in clinical dentistry for over 30 years, however, little work has been reported on their performance. In dental air turbine handpieces, the types of flow channel and turbine blade shape can have very different designs. These different designs can have major influence on the torque, rotating speed, and power performance. This research is focused on the turbine blade and the flow channel designs. Using CFD and experiments, the key design parameters which influence the performance of dental hand pieces can be studied. Three types of dental air turbine designs with different turbine blades, nozzle angles, nozzle flow channels, and shroud clearances were tested and analyzed. Very good agreement was demonstrated between the CFD analyses and the experiments. Using the analytical model, parametric studies were performed to indentify key design parameters.

Hybrid-model-based stiffness analysis of a three-revolute-prismatic-spherical parallel kinematic machine

2016 ◽  
Vol 231 (14) ◽  
pp. 2561-2576 ◽  
Author(s):  
Jun Zhang ◽  
Yan Q Zhao ◽  
Hai W Luo
Keyword(s):  
High Speed ◽  
Experimental Tests ◽  
Design Parameters ◽  
Parallel Kinematic Machine ◽  
Modeling Methodology ◽  
Parallel Kinematic ◽  
Stiffness Characteristics ◽  
And Performance ◽  
High Dynamics ◽  
Spring Constants

A three-revolute-prismatic-spherical parallel kinematic machine is proposed as an alternative solution for high-speed machining tool due to its high rigidity and high dynamics. Considering the parallel kinematic machine module as a typical compliant parallel mechanism, whose three limb assemblages have bending, extending and torsional deflections, this article proposes a hybrid modeling methodology to establish an analytical stiffness model for the three-revolute-prismatic-spherical device. The developed analytical model is further used to evaluate the stiffness mapping of the three-revolute-prismatic-spherical module over a given work plane which is then validated by experimental tests. The simulations and experiments indicate that the present hybrid methodology can predict the three-revolute-prismatic-spherical parallel kinematic machine’s stiffness in a quick and accurate manner. The solution for eigenvalue problem of the stiffness matrix leads to the stiffness characteristics of the parallel module including eigenstiffnesses and the corresponding eigenscrews as well as the equivalent screw spring constants. Based on the eigenscrew decomposition, the parallel kinematic machine is physically interpreted as a rigid platform suspending by six screw springs. The minimum, maximum and average of the screw spring constants are chosen as indices to assess the three-revolute-prismatic-spherical parallel kinematic machine’s stiffness performance. The distributions of the proposed indices throughout the workspace reveal a strong dependency on the mechanism’s configurations. At the final stage, the effects of some design parameters on system stiffness characteristics are investigated with the purpose of providing useful information for the conceptual design and performance improvement of the parallel kinematic machine.

scholarly journals CHANGE IN THE TENSILE STRENGTH OF PRESSED BIRCH WOOD DURING LOCAL CRUSHING

2021 ◽  
Author(s):  
Svetlana Snegireva ◽  
Anna Kurnikova
Keyword(s):  
High Speed ◽  
Raw Materials ◽  
Great Influence ◽  
Physical And Mechanical Properties ◽  
Rolling Stock ◽  
Birch Wood ◽  
Damping Properties ◽  
Strength Limit ◽  
Speed Performance

At present, due to the reduction of business wood stocks, the problem of using fast-growing soft hardwoods as industrial raw materials is of particular relevance. This wood has a number of disadvantages – low density, low strength indicators, which limit the scope of its application. It is possible to improve the quality of soft hardwood wood by pressing it (compacting). Compaction of wood has a great influence on the physical and mechanical properties of wood. The wide application of pressed wood is possible in the production of railway sleepers. Pressing wood significantly increases the performance properties of the sleeper beam. One of the advantages of wooden railway sleepers is their high damping properties. The presence of damping properties in wooden sleepers ensures high speed performance and a long service life of the rolling stock. In this connection, research that ensures the rational use of wood raw materials is relevant. The purpose of this study is to determine the nature of the change in the strength limit of pressed birch wood (Betula pendula) during local crumpling.

Loading and Design Parameter Uncertainty in the Dynamics and Performance of High-Speed-Parallel-Helical-Stage of a Wind Turbine Gearbox1

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Fisseha M. Alemayehu ◽  
Stephen Ekwaro-Osire
Keyword(s):  
Wind Turbine ◽  
Design Parameter ◽  
High Speed ◽  
Design Parameters ◽  
Parameter Uncertainties ◽  
Component Reliability ◽  
Input Shaft ◽  
Multibody Dynamic ◽  
Input Variables ◽  
And Performance

In operation, wind turbine gearboxes (WTGs) are subjected to variable torsional and nontorsional loads. In addition, the manufacturing and assembly process of these devices results in uncertainty in the design parameters of the system. WTGs are reported to fail in their early life of operation within 3–7 years as opposed to the expected 20 years of operation. Their downtime and maintenance process is the most costly of the failures of any subassembly of wind turbines (WTs). The objective of this work is to perform a probabilistic multibody dynamic analysis (PMBDA) of the high-speed-parallel-helical-stage (HSPHS) of a WTG that considers the uncertainties of generator-side torque-loading and input-shaft speed as well as assembly and design parameter uncertainties. Component reliability (Rc) or probability of failure (Pf) and probabilistic sensitivities of all the input variables toward five performance functions have been measured and conclusions have been drawn. As opposed to the traditional deterministic approach, PMBDA has demonstrated a new aspect of design and installation of WTGs. In addition to revealing Rc or system reliability or underperformance through Pf, the method will also help designers to critically consider certain variables through the probabilistic sensitivity results.

LIGHTING AND PERFORMANCE: AN ANALYSIS ON LIGHTING EFFICIENCY OF ARCHITECTURE STUDIO

2019 ◽  
Vol 1 (1) ◽  
pp. 92
Author(s):  
Fazidah Hanim Husain
Keyword(s):  
Learning Environment ◽  
Comfort Level ◽  
Artificial Lighting ◽  
Level Measurement ◽  
Acceptable Range ◽  
Creative Learning ◽  
Illuminance Level ◽  
And Performance ◽  
Effect Of Light

Lighting is one of the key elements in any space and building infrastructure. Good design for an area in the building requires sufficient light that contributes to the efficiency of the activities. The correct method allows natural light to transmit, reduce heat and glare in providing a conducive learning environment. Light plays a significant influence to the quality of space and contributes focus of the students in an architecture studio. Previous research has shown that the effect of light also controlled emotions, behavior, and mood of the students. The operations of artificial lighting that have been used most of the time in an architecture studio during day and night may create lavishness and inadequacy at the same time. Therefore, this paper focuses on the identifying the quality of light for the architecture studio in UiTM (Perak), to instill a creative learning environment. Several methodologies adopted in this study such as illuminance level measurement using lux meter (LM-8100), and a questionnaire survey in gauging the lighting comfort level from students’ perspective. The study revealed that the illuminance level in the architecture studio is insufficient and not in the acceptable range stated in the Malaysian: Standards 1525:2007 and  not evenly distributed.  The study also concluded that the current studio environment is not condusive and appears monotonous. 

Strategic threats to energy security as risks of quality of people's life

2020 ◽  
Vol 16 (4) ◽  
pp. 730-744
Author(s):  
V.I. Loktionov
Keyword(s):  
Quality Of Life ◽  
Energy Security ◽  
Well Being ◽  
Scientific Methods ◽  
Analysis And Synthesis ◽  
General Scientific ◽  
And Performance ◽  
Economic Well Being ◽  
The Way

Subject. The article reviews the way strategic threats to energy security influence the quality of people's life. Objectives. The study unfolds the theory of analyzing strategic threats to energy security by covering the matter of quality of people's life. Methods. To analyze the way strategic threats to energy security spread across cross-sectoral commodity and production chains and influences quality of people's living, I applied the factor analysis and general scientific methods of analysis and synthesis. Results. I suggest interpreting strategic threats to energy security as risks of people's quality of life due to a reduction in the volume of energy supply. I identified mechanisms reflecting how the fuel and energy complex and its development influence the quality of people's life. The article sets out the method to assess such quality-of-life risks arising from strategic threats to energy security. Conclusions and Relevance. In the current geopolitical situation, strategic threats to energy security cause long-standing adverse consequences for the quality of people's life. If strategic threats to energy security are further construed as risk of quality of people's life, this will facilitate the preparation and performance of a more effective governmental policy on energy, which will subsequently raise the economic well-being of people.

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