**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**913

# Search results for: Angular Velocity

##### 913 Stress Analysis for Two Fitted Thin Walled Cylinder with High Angular Velocity

**Authors:**
A.V. Hoseini,
A. Bidi,
M. H. Pol,
M.Jalali azizpour

**Abstract:**

**Keywords:**
Thin walled cylinder,
high angular velocity,
twofitted thin walled

##### 912 Acceleration Analysis of a Rotating Body

**Authors:**
R. Usubamatov

**Abstract:**

The velocity of a moving point in a general path is the vector quantity, which has both magnitude and direction. The magnitude or the direction of the velocity vector can change over time as a result of acceleration that the time rate of velocity changes. Acceleration analysis is important because inertial forces and inertial torques are proportional to rectilinear and angular accelerations accordingly. The loads must be determined in advance to ensure that a machine is adequately designed to handle these dynamic loads. For planar motion, the vector direction of acceleration is commonly separated into two elements: tangential and centripetal or radial components of a point on a rotating body. All textbooks in physics, kinematics and dynamics of machinery consider the magnitude of a radial acceleration at condition when a point rotates with a constant angular velocity and it means without acceleration. The magnitude of the tangential acceleration considered on a basis of acceleration for a rotating point. Such condition of presentation of magnitudes for two components of acceleration logically and mathematically is not correct and may cause further confusion in calculation. This paper presents new analytical expressions of the radial and absolute accelerations of a rotating point with acceleration and covers the gap in theoretical study of acceleration analysis.

**Keywords:**
acceleration analysis,
kinematics of mechanisms.

##### 911 Real Time Monitoring of Long Slender Shaft by Distributed-Lumped Modeling Techniques

**Authors:**
Sina Babadi,
K. M. Ebrahimi

**Abstract:**

**Keywords:**
Distributed Lumped modeling,
Lumped modeling,
Drill string,
Angular Velocity,
Torque.

##### 910 Analysis of Cascade Control Structure in Train Dynamic Braking System

**Authors:**
B. Moaveni,
S. Morovati

**Abstract:**

**Keywords:**
Cascade control,
dynamic braking system,
DC traction motors,
slip control.

##### 909 Velocity Filter Banks using 3-D FFT

**Authors:**
G. Koukiou,
V. Anastassopoulos

**Abstract:**

**Keywords:**
Velocity filters,
filter banks,
3-D FFT.

##### 908 A New Approach Defining Angular DMD Using Near Field Aperturing

**Authors:**
S. Al-Sowayan,
K. L. Lear

**Abstract:**

A new technique to quantify the differential mode delay (DMD) in multimode fiber (MMF) is been presented. The technique measures DMD based on angular launch and measurements of the difference in modal delay using variable apertures at the fiber face. The result of the angular spatial filtering revealed less excitation of higher order modes when the laser beam is filtered at higher angles. This result would indicate that DMD profiles would experience a data pattern dependency.

**Keywords:**
Fiber measurements,
Fiber optic communications

##### 907 Measurements of Radial Velocity in Fixed Fluidized Bed for Fischer-Tropsch Synthesis Using LDV

**Authors:**
Xiaolai Zhang,
Haitao Zhang,
Qiwen Sun,
Weixin Qian,
Weiyong Ying

**Abstract:**

**Keywords:**
LDV,
fixed fluidized bed,
velocity,
Fischer-Tropsch
synthesis.

##### 906 Stabilization of Angular-Shaped Riprap under Overtopping Flows

**Authors:**
Dilavar Khan,
Z. Ahmad

**Abstract:**

**Keywords:**
Angularity,
Gradation,
Riprap,
Stabilization

##### 905 Free Flapping Vibration of Rotating Inclined Euler Beams

**Authors:**
Chih-Ling Huang,
Wen-Yi Lin,
Kuo-Mo Hsiao

**Abstract:**

**Keywords:**
Flapping vibration,
Inclination angle,
Natural frequency,
Rotating beam.

##### 904 Characterization of Extreme Low-Resolution Digital Encoder for Control System with Sinusoidal Reference Signal

**Authors:**
Zhenyu Zhang,
Qingbin Gao

**Abstract:**

Low-resolution digital encoder (LRDE) is commonly adopted as a position sensor in low-cost and resource-constraint applications. Traditionally, a digital encoder is modeled as a quantizer without considering the initial position of the LRDE. However, it cannot be applied to extreme LRDE for which stroke of angular motion is only a few times of resolution of the encoder. Besides, the actual angular motion is substantially distorted by this extreme LRDE so that the encoder reading does not faithfully represent the actual angular motion. This paper presents a modeling method for extreme LRDE by taking into account the initial position of the LRDE. For a control system with sinusoidal reference signal and extreme LRDE, this paper analyzes the characteristics of angular motion. Specifically, two descriptors of sinusoidal angular motion are studied, which essentially sheds light on the actual angular motion from extreme LRDE.

**Keywords:**
Low resolution digital encoder,
resource-constraint control system,
sinusoidal reference signal,
servo motion control.

##### 903 A Simplified Model for Mechanical Loads under Angular Misalignment and Unbalance

**Authors:**
Úrsula B. Ferraz,
Paulo F. Seixas,
Webber E. Aguiar

**Abstract:**

This paper presents a dynamic model for mechanical loads of an electric drive, including angular misalignment and including load unbalance. The misalignment model represents the effects of the universal joint between the motor and the mechanical load. Simulation results are presented for an induction motor driving a mechanical load with angular misalignment for both flexible and rigid coupling. The models presented are very useful in the study of mechanical fault detection in induction motors, using mechanical and electrical signals already available in a drive system, such as speed, torque and stator currents.

**Keywords:**
Angular misalignment,
fault modeling,
unbalance,
universal joint.

##### 902 Velocity Distribution in Open Channels with Sand: An Experimental Study

**Authors:**
E. Keramaris

**Abstract:**

In this study, laboratory experiments in open channel flows over a sand bed were conducted. A porous bed (sand bed) with porosity of ε=0.70 and porous thickness of s΄=3 cm was tested. Vertical distributions of velocity were evaluated by using a two-dimensional (2D) Particle Image Velocimetry (PIV). Velocity profiles are measured above the impermeable bed and above the sand bed for the same different total water heights (h= 6, 8, 10 and 12 cm) and for the same slope S=1.5. Measurements of mean velocity indicate the effects of the bed material used (sand bed) on the flow characteristics (Velocity distribution and Reynolds number) in comparison with those above the impermeable bed.

**Keywords:**
Particle image velocimetry,
sand bed,
velocity distribution,
Reynolds number.

##### 901 Modeling Non-Darcy Natural Convection Flow of a Micropolar Dusty Fluid with Convective Boundary Condition

**Authors:**
F. M. Hady,
A. Mahdy,
R. A. Mohamed,
Omima A. Abo Zaid

**Abstract:**

**Keywords:**
Micropolar dusty fluid,
convective heating,
natural
convection,
MHD,
porous media.

##### 900 Cold Model Experimental Research on Particle Velocity Distribution in Gas-Solid Circulating Fluidized Bed for Methanol-to-Olefins Process

**Authors:**
Yongzheng Li,
Hongfang Ma,
Qiwen Sun,
Haitao Zhang,
Weiyong Ying

**Abstract:**

**Keywords:**
Circulating fluidized bed,
laser doppler velocimeter,
particle velocity,
radial profile.

##### 899 Numerical Evaluation of the Aerodynamic Efficiency of the Stevens and Jolly Vertical- Axis Windmill (1895)

**Authors:**
M. Raciti Castelli,
E. Benini

**Abstract:**

**Keywords:**
CFD,
vertical-axis rotor,
windmill.

##### 898 Low Air Velocity Measurement Characteristics- Variation Due to Flow Regime

**Authors:**
A. Pedišius,
V. Janušas,
A. Bertašienė

**Abstract:**

The paper depicts air velocity values, reproduced by laser Doppler anemometer (LDA) and ultrasonic anemometer (UA), relations with calculated ones from flow rate measurements using the gas meter which calibration uncertainty is ± (0.15 – 0.30) %. Investigation had been performed in channel installed in aerodynamical facility used as a part of national standard of air velocity. Relations defined in a research let us confirm the LDA and UA for air velocity reproduction to be the most advantageous measures. The results affirm ultrasonic anemometer to be reliable and favourable instrument for measurement of mean velocity or control of velocity stability in the velocity range of 0.05 m/s – 10 (15) m/s when the LDA used. The main aim of this research is to investigate low velocity regularities, starting from 0.05 m/s, including region of turbulent, laminar and transitional air flows. Theoretical and experimental results and brief analysis of it are given in the paper. Maximum and mean velocity relations for transitional air flow having unique distribution are represented. Transitional flow having distinctive and different from laminar and turbulent flow characteristics experimentally have not yet been analysed.

**Keywords:**
Laser Doppler anemometer,
ultrasonic anemometer,
air flow velocities,
transitional flow regime,
measurement,
uncertainty.

##### 897 Elastic-Plastic Transition in a Thin Rotating Disc with Inclusion

**Authors:**
Pankaj,
Sonia R. Bansal

**Abstract:**

**Keywords:**
Angular speed,
Elastic-Plastic,
Inclusion,
Rotatingdisc,
Stress,
Transition.

##### 896 A Spatial Repetitive Controller Applied to an Aeroelastic Model for Wind Turbines

**Authors:**
Riccardo Fratini,
Riccardo Santini,
Jacopo Serafini,
Massimo Gennaretti,
Stefano Panzieri

**Abstract:**

**Keywords:**
Wind turbines,
aeroelasticity,
repetitive control,
periodic systems.

##### 895 Parametric Investigation of Aircraft Door’s Emergency Power Assist System (EPAS)

**Authors:**
Marshal D. Kafle,
Jun H. Kim,
Hyun W. Been,
Kyoung M. Min,
Sung H. Kim

**Abstract:**

Fluid viscous damping systems are well suited for many air vehicles subjected to shock and vibration. These damping system work with the principle of viscous fluid throttling through the orifice to create huge pressure difference between compression and rebound chamber and obtain the required damping force. One application of such systems is its use in aircraft door system to counteract the door’s velocity and safely stop it. In exigency situations like crash or emergency landing where the door doesn’t open easily, possibly due to unusually tilting of fuselage or some obstacles or intrusion of debris obstruction to move the parts of the door, such system can be combined with other systems to provide needed force to forcefully open the door and also securely stop it simultaneously within the required time i.e. less than 8 seconds. In the present study, a hydraulic system called snubber along with other systems like actuator, gas bottle assembly which together known as emergency power assist system (EPAS) is designed, built and experimentally studied to check the magnitude of angular velocity, damping force and time required to effectively open the door. Whenever needed, the gas pressure from the bottle is released to actuate the actuator and at the same time pull the snubber’s piston to operate the emergency opening of the door. Such EPAS installed in the suspension arm of the aircraft door is studied explicitly changing parameters like orifice size, oil level, oil viscosity and bypass valve gap and its spring of the snubber at varying temperature to generate the optimum design case. Comparative analysis of the EPAS at several cases is done and conclusions are made. It is found that during emergency condition, the system opening time and angular velocity, when snubber with 0.3mm piston and shaft orifice and bypass valve gap of 0.5 mm with its original spring is used, shows significant improvement over the old ones.

**Keywords:**
Aircraft Door Damper,
Bypass Valve,
Emergency
Power Assist System,
Hydraulic Damper,
Oil viscosity.

##### 894 Despiking of Turbulent Flow Data in Gravel Bed Stream

**Authors:**
Ratul Das

**Abstract:**

The present experimental study insights the decontamination of instantaneous velocity fluctuations captured by Acoustic Doppler Velocimeter (ADV) in gravel-bed streams to ascertain near-bed turbulence for low Reynolds number. The interference between incidental and reflected pulses produce spikes in the ADV data especially in the near-bed flow zone and therefore filtering the data are very essential. Nortek’s Vectrino four-receiver ADV probe was used to capture the instantaneous three-dimensional velocity fluctuations over a non-cohesive bed. A spike removal algorithm based on the acceleration threshold method was applied to note the bed roughness and its influence on velocity fluctuations and velocity power spectra in the carrier fluid. The velocity power spectra of despiked signals with a best combination of velocity threshold (VT) and acceleration threshold (AT) are proposed which ascertained velocity power spectra a satisfactory fit with the Kolmogorov “–5/3 scaling-law” in the inertial sub-range. Also, velocity distributions below the roughness crest level fairly follows a third-degree polynomial series.

**Keywords:**
Acoustic Doppler Velocimeter,
gravel-bed,
spike removal,
Reynolds shear stress,
near-bed turbulence,
velocity power spectra.

##### 893 Characteristics of Turbulent Round Jets in its Potential-Core Region

**Authors:**
S. Sivakumar,
Ravikiran Sangras,
Vasudevan Raghavan

**Abstract:**

**Keywords:**
Contoured nozzle,
hot-wire anemometer,
Reynolds
number,
velocity fluctuations,
velocity spectra.

##### 892 Terminal Velocity of a Bubble Rise in a Liquid Column

**Authors:**
Mário A. R. Talaia

**Abstract:**

**Keywords:**
Bubbles,
terminal velocity,
two phase-flow,
vertical
column.

##### 891 Angular-Coordinate Driven Radial Tree Drawing

**Authors:**
Farshad Ghassemi Toosi,
Nikola S. Nikolov

**Abstract:**

We present a visualization technique for radial drawing of trees consisting of two slightly different algorithms. Both of them make use of node-link diagrams for visual encoding. This visualization creates clear drawings without edge crossing. One of the algorithms is suitable for real-time visualization of large trees, as it requires minimal recalculation of the layout if leaves are inserted or removed from the tree; while the other algorithm makes better utilization of the drawing space. The algorithms are very similar and follow almost the same procedure but with different parameters. Both algorithms assign angular coordinates for all nodes which are then converted into 2D Cartesian coordinates for visualization. We present both algorithms and discuss how they compare to each other.

**Keywords:**
Radial Tree Drawing,
Real-Time Visualization,
Angular Coordinates,
Large Trees.

##### 890 Evaluation of Carbon Dioxide Pressure through Radial Velocity Difference in Arterial Blood Modeled by Drift Flux Model

**Authors:**
Aicha Rima Cheniti,
Hatem Besbes,
Joseph Haggege,
Christophe Sintes

**Abstract:**

**Keywords:**
Mean carbon dioxide pressure,
mean mixture pressure,
mixture velocity,
radial velocity difference.

##### 889 Measurement of Steady Streaming from an Oscillating Bubble Using Particle Image Velocimetry

**Authors:**
Yongseok Kwon,
Woowon Jeong,
Eunjin Cho,
Sangkug Chung,
Kyehan Rhee

**Abstract:**

Steady streaming flow fields induced by a 500 mm bubble oscillating at 12 kHz were measured using microscopic particle image velocimetry (PIV). The accuracy of velocity measurement using a micro PIV system was checked by comparing the measured velocity fields with the theoretical velocity profiles in fully developed laminar flow. The steady streaming flow velocities were measured in the sagittal plane of the bubble attached on the wall. Measured velocity fields showed upward jet flow with two symmetric counter-rotating vortices, and the maximum streaming velocity was about 12 mm/s, which was within the velocity ranges measured by other researchers. The measured streamlines were compared with the analytical solution, and they also showed a reasonable agreement.

**Keywords:**
Oscillating bubble,
Particle-Image-Velocimetry microstreaming.

##### 888 Assessing the Effect of Grid Connection of Large-Scale Wind Farms on Power System Small-Signal Angular Stability

**Authors:**
Wenjuan Du,
Jingtian Bi,
Tong Wang,
Haifeng Wang

**Abstract:**

**Keywords:**
power system small-signal angular stability,
power system low-frequency oscillations,
electromechanical oscillation modes,
wind farms,
double fed induction generator (DFIG)

##### 887 Oscillatory Electroosmotic Flow of Power-Law Fluids in a Microchannel

**Authors:**
Rubén Bãnos,
José Arcos,
Oscar Bautista,
Federico Méndez

**Abstract:**

**Keywords:**
Oscillatory electroosmotic flow,
Non-Newtonian
fluids,
power-law model,
low zeta potentials.

##### 886 Investigation of Self-Similarity Solution for Wake Flow of a Cylinder

**Authors:**
A. B. Khoshnevis,
F. Zeydabadi,
F. Sokhanvar

**Abstract:**

**Keywords:**
Self-similarity,
wake of single circular cylinder

##### 885 Design and Motion Control of a Two-Wheel Inverted Pendulum Robot

**Authors:**
Shiuh-Jer Huang,
Su-Shean Chen,
Sheam-Chyun Lin

**Abstract:**

Two-wheel inverted pendulum robot (TWIPR) is designed with two-hub DC motors for human riding and motion control evaluation. In order to measure the tilt angle and angular velocity of the inverted pendulum robot, accelerometer and gyroscope sensors are chosen. The mobile robot’s moving position and velocity were estimated based on DC motor built in hall sensors. The control kernel of this electric mobile robot is designed with embedded Arduino Nano microprocessor. A handle bar was designed to work as steering mechanism. The intelligent model-free fuzzy sliding mode control (FSMC) was employed as the main control algorithm for this mobile robot motion monitoring with different control purpose adjustment. The intelligent controllers were designed for balance control, and moving speed control purposes of this robot under different operation conditions and the control performance were evaluated based on experimental results.

**Keywords:**
Balance control,
speed control,
intelligent controller and two wheel inverted pendulum.

##### 884 Gas Pressure Evaluation through Radial Velocity Measurement of Fluid Flow Modeled by Drift Flux Model

**Authors:**
Aicha Rima Cheniti,
Hatem Besbes,
Joseph Haggege,
Christophe Sintes

**Abstract:**

In this paper, we consider a drift flux mixture model of the blood flow. The mixture consists of gas phase which is carbon dioxide and liquid phase which is an aqueous carbon dioxide solution. This model was used to determine the distributions of the mixture velocity, the mixture pressure, and the carbon dioxide pressure. These theoretical data are used to determine a measurement method of mean gas pressure through the determination of radial velocity distribution. This method can be applicable in experimental domain.

**Keywords:**
Mean carbon dioxide pressure,
mean mixture pressure,
mixture velocity,
radial velocity.