Showing items 1 - 20 of 66

Your selections:

Positive displacement machines : Modern design innovations and tools

- Sultan, Ibrahim, Phung, Truong

  • Authors: Sultan, Ibrahim , Phung, Truong
  • Date: 2019
  • Type: Text , Book
  • Relation: Positive Displacement Machines: Modern Design Innovations and Tools
  • Full Text: false
  • Reviewed:
  • Description: Positive Displacement Machines: Modern Design Innovations and Tools explains the design and workings of a wide range of positive displacement pumps, compressors and gas expanders. Written at a mathematical and technical level, the book explores the most influential research in this field over the past decade, along with industry best practices. Sections highlight the importance of using the latest computation techniques and discuss how to follow the proper design procedures to achieve a desired outcome. © 2020 Elsevier Inc. All rights reserved.

Improving torque performance in reciprocating compressors via asymmetric stroke characteristics

- Sultan, Ibrahim, Phung, Truong

  • Authors: Sultan, Ibrahim , Phung, Truong
  • Date: 2019
  • Type: Text , Book chapter
  • Relation: Positive Displacement Machines: Modern Design Innovations and Tools p. 145-162
  • Full Text: false
  • Reviewed:
  • Description: Reciprocating compressors enjoy a considerable popularity in industry due to their ability to attain high pressure levels at a range of crankshaft speeds. This chapter is intended to show that it is possible to obtain a considerable improvement in the performance of these compressors by modifying the design of their drives. Instead of the traditional slider-crank mechanism which has been used as a drive since the compressor industry started, it is now possible to replace this drive by more sophisticated ones which feature more flexible stroke designs. The chapter will offer a mathematical model for the workings of reciprocating compressor and demonstrate a candidate drive linkage. An example, presented at the end of the chapter, will demonstrate how the candidate drive linkage is optimized to reduce the torque acting on the compressor crank shaft and hence improve operation and reduce the stresses acting on various components. © 2020 Elsevier Inc. All rights reserved.

Model-free subspace based dynamic control of mechanical manipulators

- Saleem, Muhammad Saad, Sultan, Ibrahim

Inverse position procedure for manipulators with rotary Joints

- Sultan, Ibrahim

A technique for the independent-axis calibration of robot manipulators with experimental verification

- Sultan, Ibrahim, Wager, John

  • Authors: Sultan, Ibrahim , Wager, John
  • Date: 2001
  • Type: Text , Journal article
  • Relation: International Journal of Computer Integrated Manufacturing Vol. 14, no. 5 (2001), p. 501-512
  • Full Text:
  • Reviewed:
  • Description: Accurate use of robots in an off-line programming mode is only possible through a proper calibration procedure. In this procedure, the end-effector is made to move along a set of known spatial poses where the positional errors are to be measured and employed in mathematical models. The models are subsequently solved for the manipulator dimensions (geometric parameters) using suitable regression techniques. Calibration is usually performed using either aggregate or independent-axis models. While the aggregate models result in all the system parameters being worked out simultaneously, the independent-axis models are meant to work out the geometric particulars of each joint-axis individually. In the present work, the independent-axis technique is used for the analysis with new mathematical models proposed to overcome the drawbacks of the existing methods. Moreover, the techniques employed here result in the prediction of transmission error functions and the modelling of the joint motion dependencies. This is a new concept in the field of robot calibration. Finally, the models proposed have been used to calibrate an ASEA IRB/L6 robot and the results are reported at the end of the paper.

A phi-model solution for the inverse position problem of calibrated robots using virtual elementary motions

- Sultan, Ibrahim, Wager, John

  • Authors: Sultan, Ibrahim , Wager, John
  • Date: 2001
  • Type: Text , Journal article
  • Relation: Inverse Problems in Engineering Vol. 9, no. 3 (2001), p. 261-285
  • Full Text:
  • Reviewed:
  • Description: It is central to the control of manipulators to calculate the set/sets of joint-displacements which correspond to a given spatial pose (position and orientation) of the end-effector. This problem, which is referred to as the inverse position problem, represents one of the most difficult mathematical challenges in the field of robotics, particularly when performed for calibrated robots (or robots with general structures). In such cases, closed form solutions are too impractical to implement and iterative solutions suffer from numerical singularities. In the present work a procedure is introduced to obtain multiple inverse position solutions for serial robotic structures. For calibrated robots, the procedure involves a simple iterative technique designed to ensure fast convergence and eliminate the occurrence of singularity. However, inverse position solutions for spherical-wrist manipulators will be obtained in a straight-forward non-iterative fashion. A published kinematic notation, referred to as the phi -model, was used to develop the system equations.

A geometric design model for the circolimacon positive displacement machine

- Sultan, Ibrahim

  • Authors: Sultan, Ibrahim
  • Date: 2008
  • Type: Text , Journal article
  • Relation: Journal of Mechanical Design Vol. 130, no. 6 (Jun 2008), p. 8
  • Full Text: false
  • Reviewed:
  • Description: A circolimacon positive displacement machine is driven by a lima on mechanism, but the profiles of its rotor and housing are circular arcs. As such, its design models are different from those of the lima on-to-lima on machines, whose profiles are cut to the limacon equations. For the benefit of the reader the paper starts with a brief background on the general geometric aspects of the limacon fluid processing technology. However the focus is then turned to the circolimacon machine, where its design parameters are introduced and geometric models are proposed to assist with the design process. Also, a computational inverse design model has been employed to work out a set of congruent geometric parameters to meet certain design requirements. Case studies are presented at the end of the paper to give the reader a numerical perspective on the design process of this class of positive displacement machines.
  • Description: C1

A surrogate model for interference prevention in the limaçon-to-limaçon machines

- Sultan, Ibrahim

  • Authors: Sultan, Ibrahim
  • Date: 2007
  • Type: Text , Journal article
  • Relation: Engineering Computations (Swansea, Wales) Vol. 24, no. 5 (2007), p. 437-449
  • Full Text:
  • Reviewed:
  • Description: Purpose - This paper aims to replace the complicated iterative procedure used to prevent interference in limacon-to-limacon machines by a simplified mathematical equation which can be solved by a straightforward substitution of the required clearance value. Design/methodology/approach - The input data to the iterative procedure and the obtained results have been employed in regression models to construct the sought after equation. Searching for a proper form of this equation involved numerical experiments to study the effects of the various model parameters on the system response. Findings - The numerical experiments conducted proved to be an effective model construction technique, and the regression model proposed has been found extremely accurate in the specified parameter space. Research limitations/implications - The proposed equation is applicable within the parameter range chosen for the study. This range is the one often used for industrial applications. Should the parameters selected for a specific design fall outside the specified range, the proposed model structure may have to be varied to maintain a desirable level of accuracy. Practical implications - The interference study is a part of the iterative procedure employed to design the dimensions of the limaçon-to-limaçon machine. This iterative procedure searches for the proper design amongst hundreds of various possible solutions. The results of this paper will ensure a much faster convergence for the design procedure, since the interference study will be eliminated from the iterative section of the analysis. Originality/value - The paper offers a valid and accurate model that can be efficiently used for the intended purpose. © Emerald Group Publishing Limited.
  • Description: C1
  • Description: 2003004799

Inverse geometric design for a class of rotary positive displacement machines

- Sultan, Ibrahim

  • Authors: Sultan, Ibrahim
  • Date: 2008
  • Type: Text , Journal article
  • Relation: Inverse Problems in Science and Engineering Vol. 16, no. 2 (2008), p. 127-139
  • Full Text: false
  • Reviewed:
  • Description: Inverse design techniques in the area of fluid mechanics are normally conducted for continuous flow turbomachines rather than positive displacement devices. However, the work in this article is concerned with a class of rotary positive displacement device referred to as the limaçon-to-limaçon machine. The rotors and housings of these machines are manufactured of limaçon profiles, and are likely to suffer from interference if the rotors are not carefully profiled. Published literature indicates that solutions proposed to tackle the interference problem in these machines will adversely affect their efficiency figures. This notion motivated the work presented in this article, which first introduces the relevant mathematical models of the limaçon-to-limaçon machine and then uses these models to construct an inverse geometric design problem formulation. The proposed model has been coded in a computer program that utilises a Marquardt-Levenberg technique to converge to the required geometric parameters. Case studies are presented at the end of the article to verify the validity of the proposed inverse design model.
  • Description: C1

Feasibility of subspace identification for bipeds an innovative approach for kino-dynamic systems

- Saleem, Muhammad Saad, Sultan, Ibrahim

Kinematic modelling of a new gear: Coupled mechanism

- Sultan, Ibrahim

A numerical solution for determinantal polynomials with application to robot kinematics

- Sultan, Ibrahim

Introduction

- Sultan, Ibrahim, Phung, Truong

Profiling rotors for limacon-to-limacon compression-expansion machines

- Sultan, Ibrahim

  • Authors: Sultan, Ibrahim
  • Date: 2006
  • Type: Text , Journal article
  • Relation: Journal of Mechanical Design Vol. 128, no. 4 (Jul 2006), p. 787-793
  • Full Text: false
  • Reviewed:
  • Description: Limaçon-to-limaçon compression-expansion machines have housings and rotors whose profiles are manufactured of limaçon curves. For these machines to perform satisfactorily, extreme care should be given to the geometric particulars of their rotor profile. The main characteristics that govern the quality of the rotor profile are the volumetric efficiency and the prevention of interference. In this work, the interference problem is handled from two different mathematical standpoints: the slope of tangents to both the rotor and housing curves at the apices; and the value of the minimum radial clearance that separates the two limaçon curves. In the first case, mathematical expressions, relating the radii of the limaçon base circles is presented to ensure that interference would not take place during normal operations of the limaçon-to-limaçon machine. The second mode of analysis produces a set of nonlinear equations that can be solved to obtain a value of the radial clearance. This value has to be machined off the rotor profile to prevent interference. A numerical example is given at the end of the paper to prove the validity of the models proposed and graphs are produced to support the claims presented.
  • Description: C1
  • Description: 2003001971

The limacon of Pascal : mechanical generation and utilization for fluid processing

- Sultan, Ibrahim

  • Authors: Sultan, Ibrahim
  • Date: 2005
  • Type: Text , Journal article
  • Relation: Proceedings of the Institution of Mechanical Engineers Part C-Journal of Mechanical Engineering Science Vol. 219, no. 8 (Aug 2005), p. 813-822
  • Full Text:
  • Reviewed:
  • Description: The limaçon of Pascal is a plane curve that possesses some characteristics which qualify it for fluid processing applications. However, the curve has not yet attracted enough attention, neither from industry nor from the mechanical engineering research community, despite the few attempts that have been conducted over the past century. The work presented here is intended to explore various mechanical linkages that can be employed to produce the limaçon and the aspects of these linkages. Mathematical analysis will show that machines based on the limaçon curve possess sinusoidal volumetric relationships and hence, simplified pressure and torque equations can be obtained in closed forms. The concepts discussed here will be demonstrated by using a compressor as a sample application
  • Description: C1
  • Description: 2003001087

Introducing differential kinematics to mechanical engineering students

- Sultan, Ibrahim

  • Authors: Sultan, Ibrahim
  • Date: 2009
  • Type: Text , Journal article
  • Relation: International Journal of Mechanical Engineering Education Vol. 37, no. 3 (2009), p. 210-222
  • Full Text:
  • Description: Differential kinematics offers a simplified alternative to closed-form input-output equations needed to study the geometrical behaviour of linkages. For most linkages, these closed-form equations are either too messy or not possible to obtain, a fact that sometimes reflects negatively on how mechanical engineering students perceive the subject of mechanism analysis. On the other hand, differential models can easily be utilised in numerical methods designed to encourage these students to tackle even more difficult problems than currently being considered in academic programmes. In this paper, an approach is presented to facilitate this process. The mathematical procedure is based on the use of matrices referred to as kinematic Jacobians. The determinants of these matrices offer invaluable insights into the linkage mobility. These matrices are explained and used in a practice numerical example.
  • Description: 2003008219

Vibration analysis : Optimization of parameters of the two mass model based on Kelvin elements

- Kuznetsov, Alexey, Mammadov, Musa, Sultan, Ibrahim, Hajilarov, Eldar

A novel in-vehicle real-time brake-monitoring system

- Fumi, Duncan, Sultan, Ibrahim

  • Authors: Fumi, Duncan , Sultan, Ibrahim
  • Date: 2009
  • Type: Text , Journal article
  • Relation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering Vol. 223, no. 6 (2009), p. 793-804
  • Full Text:
  • Reviewed:
  • Description: The design of vehicle brake systems involves optimizing a large number of competing parameters. In order to find an appropriate balance of properties, it is important to have a good picture of the range of operating conditions that the system will operate under. Obtaining such information for a large range of driving conditions requires recording data over a long period of time from a number of vehicles under various driving conditions. In this paper, a proposed data acquisition system has been designed, constructed, and implemented to measure and to store in real time the performance-related parameters of brake systems. The system proposed here to monitor brake performance employs a small embedded personal computer together with a number of peripheral cards as its basis. As a part of the validation process, recordings have been made of some long-term test sequences during a brake development programme. The results, which would be considered representative of normal confident driving, are given and discussed at the end of the paper. These results are used to monitor brake performance and do offer valuable guidance for future brake design projects. © IMechE 2009.

Characterisation of slug flow conditions in pipelines for fatigue analysis

- Reda, Ahmed, Forbes, Gareth, Sultan, Ibrahim

  • Authors: Reda, Ahmed , Forbes, Gareth , Sultan, Ibrahim
  • Date: 2011
  • Type: Text , Conference proceedings
  • Full Text: false
  • Description: Understanding the problem of slug flow induced fatigue damage is of particular importance to the reliable operation of pipelines. Slug flow across unsupported pipeline spans, pipeline crossings or vertical engineered buckle initiators, i.e. sleepers, produces dynamic motion in the pipeline resulting in cyclic fatigue stresses. In some cases, the dynamic effects will cause the pipeline to fail at a point of stress concentration. In other cases, however, these effects may be negligible. The current literature provides no guidance as to when the dynamic effects of slug flow must be considered. This paper gives guidance and describes how fatigue due to slug flow in pipelines, which would normally require dynamic analysis, can be quantified using simplified quasi-static analysis. The paper also presents a design process which could be used by pipeline engineers to determine the level of analysis needed, before embarking on more complex and expensive dynamic finite element. Copyright © 2011 by ASME.

A surrogate model for evaluation of maximum normalized dynamic load factor in moving load model for pipeline spanning due to slug flow

- Sultan, Ibrahim, Reda, Ahmed, Forbes, Gareth

  • Authors: Sultan, Ibrahim , Reda, Ahmed , Forbes, Gareth
  • Date: 2012
  • Type: Text , Conference proceedings
  • Full Text:
  • Description: Understanding the problem of slug-flow-induced fatigue damage is of particular importance to the reliable operation of pipelines. Slug flow, across unsupported pipeline spans, produces dynamic vibrations in the pipeline resulting in cyclical fatigue stresses. These dynamic effects will cause the pipeline to fail at a point of stress concentration if proper design procedure is not followed. The response of a pipeline span, under the passage of slug flow, can be represented by dynamic load factors that are functions of the speed ratio and damping characteristics of the span. The aspects of these functional relationships are investigated, in this paper by conducting multiple simulations at different speed ratios and damping factors. The data obtained from the steady state Fourier expansion will, consequently, be used to produce a surrogate model with a level of accuracy that adequately qualifies it for use in determining dynamic loading of pipelines. The closed-form surrogate model can be used to eliminate the need to employ costly mathematical procedures or finite element packages for the analysis. The model will also provide a solid ground for optimization studies and help designers gain an insight into how various model parameters impact the system response. This paper will demonstrate the aspects of a proposed surrogate model and endeavor to obtain parameter domains within which the model's reliability is ensured. A numerical example will be demonstrated to prove the concepts presented in the paper and confirm the validity of the proposed model. Copyright © 2012 by ASME.
  • Description: C1