An angular velocity profile in cycling derived from mechanical energy analysis

1991 ◽  
Vol 24 (7) ◽  
pp. 577-586 ◽  
Author(s):  
M.L. Hull ◽  
Steve Kautz ◽  
Andrew Beard
Keyword(s):  
Angular Velocity ◽  
Velocity Profile ◽  
Energy Analysis ◽  
Mechanical Energy ◽  
Angular Velocity Profile

Velocity Control of a Cylindrical Rolling Robot by Surface-Morphing

2015 ◽  
Author(s):  
Michael Puopolo ◽  
J. D. Jacob
Keyword(s):  
Mathematical Model ◽  
Angular Velocity ◽  
Velocity Profile ◽  
Average Velocity ◽  
Equations Of Motion ◽  
Angular Position ◽  
Velocity Control ◽  
Control Scheme ◽  
Rolling Robot ◽  
Angular Velocity Profile

A mathematical model is developed for a rolling robot with a cylindrically-shaped, elliptical outer surface that has the ability to alter its shape as it rolls, resulting in a torque imbalance that accelerates or decelerates the robot. A control scheme is implemented, whereby angular position and angular velocity are used as feedback to trigger and define morphing actuation. The goal of the control is to direct the robot to follow a given angular velocity profile. Equations of motion for the rolling robot are formulated and solved numerically. Results show that by automatically morphing its shape in a periodic fashion, the rolling robot is able to start from rest, achieve constant average velocity and slow itself in order to follow a desired velocity profile with significant accuracy.

Tracking Control of a Software Cam Machining System

1999 ◽  
Vol 121 (4) ◽  
pp. 729-735 ◽  
Author(s):  
Mi-Ching Tsai ◽  
Yaw-Hwei Lee
Keyword(s):  
Control System ◽  
Angular Velocity ◽  
Velocity Profile ◽  
Tracking Control ◽  
Contact Point ◽  
Tangential Velocity ◽  
Position Tracking ◽  
Servo Motor ◽  
Cam Profile ◽  
Angular Velocity Profile

This paper presents a software cam manufacturing system. It includes a position tracking control system, a programmable cam profile, and a programmable variable angular velocity profile. The position tracking system consists of a rotary direct drive (DD) servo motor and a linear servo-motor. The rotary DD servo-motor is controlled to track the variable angular velocity profile, while the linear servo-motor is controlled to synchronously track the desired cam profile. Such a tracking control system is proposed to achieve a constant removal rate for fine machining (i.e., the relative tangential velocity at the contact point should be constant). A numerical method for off-line derivation of the variable angular velocity profile with respect to the desired cam profile is developed to achieve constant relative tangential velocity at the contact point. An experimental tracking control system with two servo controllers is developed to study the feasibility of this approach.

Creating the Wind Energy for Operating the 3-C-Section Blades Wind Car

2012 ◽  
Vol 622-623 ◽  
pp. 1188-1193 ◽  
Author(s):  
Hüseyin Çamur ◽  
Youssef Kassem
Keyword(s):  
Wind Speed ◽  
Angular Velocity ◽  
Wind Energy ◽  
Drag Force ◽  
Mechanical Energy ◽  
Main Shaft ◽  
Airflow Velocity ◽  
Low Speed ◽  
Low Wind Speed

The purpose of this work is to determine the drag characteristics and the torque of three C-section blades wind car. Three C-section blades are directly connected to wheels by using of various kinds of links. Gears are used to convert the wind energy to mechanical energy to overcome the load exercised on the main shaft under low speed. Previous work on three vertical blades wind car resulted in discrepancies when compared to this work. Investigating these differences was the motivation for this series of work. The calculated values were compared to the data of three vertical blades wind car. The work was conducted in a low wind speed. The drag force acting on each model was calculated with an airflow velocity of 4 m/s and angular velocity of the blade of 13.056 rad/s.

scholarly journals Determining the Tangential Velocity profile of a Rotating Fluid in a Static Container using Navier–Stokes equations

2020 ◽  
Author(s):  
RAJDEEP TAH ◽  
SARBAJIT MAZUMDAR ◽  
Krishna Kant Parida
Keyword(s):  
Angular Velocity ◽  
Velocity Profile ◽  
Velocity Gradient ◽  
Stokes Equations ◽  
Tangential Velocity ◽  
Navier Stokes ◽  
Rotating Fluid ◽  
Navier Stokes Equations ◽  
Similar Principle ◽  
Tangential Velocity Profile

The shape of the liquid surface for a fluid present in a uniformly rotating cylinder is generally determined by making a Tangential velocity gradient along the radius of the rotating cylindrical container. A very similar principle can be applied if the direction of the produced velocity gradient is reversed, for which the source of rotation will be present at the central axis of the cylindrical vessel in which the liquid is present. Now if the described system is completely closed, the angular velocity will decrease as a function of time. But when the surface of the rotating fluid is kept free, then the Tangential velocity profile would be similar to that of the Taylor-Couette Flow, with a modification that; due to formation of a curvature at the surface, the Navier-Stokes law is to be modified. Now the final equation may not seem to have a proper general solution, but can be approximated to certain solvable expressions for specific cases of angular velocity.

A Theoretical Analysis of the Influence of Rotation on Flow in a Tube Rotating about a Parallel Axis with Uniform Angular Velocity

1965 ◽  
Vol 69 (651) ◽  
pp. 201-202 ◽  
Author(s):  
W. D. Morris
Keyword(s):  
Angular Velocity ◽  
Velocity Profile ◽  
Axial Velocity ◽  
Cylindrical Tube ◽  
Fluid Flows ◽  
Leading Edge ◽  
Pressure Fields ◽  
Axial Velocity Profile ◽  
Parallel Axis ◽  
Arbitrary Axis

When fluid flows in a tube which rotates about an arbitrary axis, the presence of centripetal and Coriolis acceleration components modify the velocity and pressure fields which exist in the absence of rotation. Barua considered the case of an incompressible fluid flowing in laminar motion through a cylindrical tube which was rotating about an axis perpendicular to itself with uniform angular velocity. For distances well away from the tube entrance Barua illustrated that secondary flow in the r-θ plane occurred and that the axial velocity profile was distorted towards the leading edge of the tube. Since the pressure gradient along the tube is proportional to the gradient of the axial velocity profile at the tube wall the rotation thus has a consequential influence on the resistance to flow offered by the tube.

scholarly journals The 3D Happel model for complete isotropic Stokes flow

2004 ◽  
Vol 2004 (46) ◽  
pp. 2429-2441 ◽  
Author(s):  
George Dassios ◽  
Panayiotis Vafeas
Keyword(s):  
Angular Velocity ◽  
Stokes Flow ◽  
Total Pressure ◽  
Mechanical Energy ◽  
Creeping Flow ◽  
Spherical Particles ◽  
Mathematical Treatment ◽  
Normal Velocity ◽  
Tensor Fields ◽  
Concentric Spheres

The creeping flow through a swarm of spherical particles that move with constant velocity in an arbitrary direction and rotate with an arbitrary constant angular velocity in a quiescent Newtonian fluid is analyzed with a 3D sphere-in-cell model. The mathematical treatment is based on the two-concentric-spheres model. The inner sphere comprises one of the particles in the swarm and the outer sphere consists of a fluid envelope. The appropriate boundary conditions of this non-axisymmetric formulation are similar to those of the 2D sphere-in-cell Happel model, namely, nonslip flow condition on the surface of the solid sphere and nil normal velocity component and shear stress on the external spherical surface. The boundary value problem is solved with the aim of the complete Papkovich-Neuber differential representation of the solutions for Stokes flow, which is valid in non-axisymmetric geometries and provides us with the velocity and total pressure fields in terms of harmonic spherical eigenfunctions. The solution of this 3D model, which is self-sufficient in mechanical energy, is obtained in closed form and analytical expressions for the velocity, the total pressure, the angular velocity, and the stress tensor fields are provided.

Energy Analysis of Liquid Desiccant Based Evaporative Cooling System

2005 ◽  
Author(s):  
Faleh A. Al-Sulaiman ◽  
P. Gandhidasan
Keyword(s):  
Thermal Energy ◽  
Energy Analysis ◽  
Cooling System ◽  
Mechanical Energy ◽  
Evaporative Cooling ◽  
Zeolite Membrane ◽  
Solution Temperature ◽  
Regeneration System ◽  
Liquid Desiccant ◽  
Evaporative Cooling System

This paper presents preliminary findings of the energy analysis of a cooling system with multistage evaporative coolers using liquid desiccant dehumidifier between the stages. The proposed evaporative cooling system utilizes the air humidity for cooling in humid areas and requires no additional water supply. The major energy requirement associated with this cooling system is the energy for regenerating the weak liquid desiccant. In this paper two types of energy namely thermal energy as well as mechanical energy are considered for regeneration. For thermal energy, the heat input for regeneration is supplied from the conventional energy sources such as a simple line heater. Reverse osmosis (RO) process is considered for regeneration by mechanical energy and MFI zeolite membrane is proposed for separation of water from the weak desiccant solution. Energy analysis has been carried out for both methods of regeneration. The results show that the energy consumption is about 25% less for the mechanical regeneration system with 3 % recovery than the thermal energy regeneration system to increase the desiccant solution temperature of 22°C. The COP of the proposed cooling system is defined as the cooling effect by the mass rate of water evaporated in the system divided by the amount of energy supplied to the system, that is, the COP is independent of the energy source.

A Study on Dimension Synthesis for the Peaucellier Mechanism

2011 ◽  
Author(s):  
Jessica Buckley ◽  
Ming Z. Huang
Keyword(s):  
Angular Velocity ◽  
Velocity Profile ◽  
Kinematic Analysis ◽  
Assembly Line ◽  
Oil Wells ◽  
Straight Line ◽  
Correct Ratio ◽  
The Creation

Straight-line motion, albeit simple, manifest itself in numerous applications, from running steam engines and oil wells to manufacturing parts with straight edges and sides. The drive to maximize production creates a need for continuously running assembly-line manufacturing comprised of precise, individually optimized components. While there are many so-called straight-line generating mechanisms, few actually produce a true straight-line, most generate only approximate straight-line. Featured an eight-link rhomboidal system with length constraints, the Peaucellier mechanism is one that actually produces a true straight line intrinsically. This paper presents a study on the dimension synthesis of the Peaucellier mechanism, namely by identifying the correct ratio of linkage lengths to produce the longest straight line stroke. In addition to designing for stroke, another objective of interest is to attain a desired velocity profile along the path. Kinematic analysis of the velocity profile on the mechanism will render the creation of input angular velocity standards based on desired stroke speed. Given the stroke and velocity specifications, specific steps to size the dimensions of the mechanism developed as result of this study will be presented.

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