A First Principle Engine Model for Up-Front Design: Further Studies on Hydrodynamic Bearing Models

2002 ◽  
Author(s):  
Zheng-Dong Ma ◽  
N. C. Perkins
Keyword(s):  
Equations Of Motion ◽  
Hydrodynamic Bearing ◽  
Engine Model ◽  
Engine Modeling ◽  
Design Changes ◽  
Engine Design ◽  
Design Cycle ◽  
Minimum Number ◽  
Dynamics And Vibration ◽  
Engine Systems

The design of a conceptually new engine system requires an engineering tool that can quickly estimate effects of the design changes on NVH and durability at the very onset of the engine design cycle. In (Ma, et al., 2000 and Ma and Perkins 2001), we presented an engine modeling template (EngTmp) to support up-front design of engine systems. The EngTmp employs a recursive formulation of multibody dynamics that leads to the minimum number of equations of motion to represent engine dynamics and vibration. The engine models generated from the EngTmp thus enjoy greater computational efficiency. The objective of this paper is to provide some further discussions on the hydrodynamic bearing models employed in the EngTmp and numerical results obtained recently for the sample engine. The attention will be focused on discussing effects of employing different hydrodynamic bearing models based on the Reynolds equation.

A First Principle Engine Model for Up-Front Design: Bearing Models and Example Results

2001 ◽  
Author(s):  
Zheng-Dong Ma ◽  
N. C. Perkins
Keyword(s):  
Equations Of Motion ◽  
Differential Algebraic Equations ◽  
Algebraic Equations ◽  
Hydrodynamic Bearing ◽  
Engine Model ◽  
Trade Offs ◽  
Engine Design ◽  
Design Cycle ◽  
Relative Coordinates ◽  
Noise Vibration

Abstract The design of new engine concepts requires an engineering tool that can quickly estimate noise, vibration and durability metrics at the very onset of the engine design cycle. In (Ma et al., 2000), we presented an engine modeling template (EMT) to support up-front engine design. The engine models generated from the EMT use the minimum set of generalized coordinates to represent engine dynamics. This is achieved by employing a pre-selected set of relative coordinates. The resulting engine model is cast as a (minimum) set of ordinary differential equations in lieu of the differential-algebraic equations that result from using commercial multibody dynamics codes. The resulting models then enjoy greater computational efficiency. In (Ma et al., 2000), we formulate the equations of motion for the engine and its major components. The objective of this paper is to review the numerical results obtained from sample engine designs and to discuss several tradeoffs between model accuracy and efficiency. Attention focuses on the trade-offs resulting from several bearing models, including linear and nonlinear spring-damper bearing models, and hydrodynamic bearing models based on the Reynolds equation. Results computed using these bearing models are critically compared.

Engine Modeling With Inlet and Exhaust Wave Action for Real Time Control

2003 ◽  
Author(s):  
Yuh-Yih Wu ◽  
Bo-Chiuan Chen ◽  
Yaojung Shiao ◽  
Feng-Chi Hsieh
Keyword(s):  
Spark Ignition Engine ◽  
Real Time Control ◽  
Combustion Heat ◽  
Engine Model ◽  
Engine Modeling ◽  
Time Control ◽  
Engine Design ◽  
Proposed Model ◽  
And Control ◽  
Work Done

A motorcycle engine model in MATLAB/SIMULINK is introduced in this paper for engine design and control system design. It simulates a 125 cc single cylinder four-stroke spark ignition engine. Sub-models include: inlet/exhaust, combustion, heat transfer, friction, and work done. The method of characteristics is used for calculating the inlet and exhaust flow. Simulated results of bmep, imep, fmep, heat release rate, inlet/exhaust pressure, and cylinder pressure were compared with the experimental data. It was found that satisfactory simulation results were achieved for the proposed model.

A First Principle Engine Model for Up-Front Design

2000 ◽  
Author(s):  
Zheng-Dong Ma ◽  
N. C. Perkins ◽  
Sheng-Jiaw Hwang
Keyword(s):  
Engine Performance ◽  
Computer Aided Engineering ◽  
Nonlinear Frequency ◽  
Noise And Vibration ◽  
Engine Mounts ◽  
Design Concepts ◽  
Engine Model ◽  
Engine Design ◽  
Design Cycle ◽  
Computer Aided

Abstract Computer-aided engineering is traditionally employed to evaluate existing engine designs or very mature designs for which detailed design information exists. The analyses are performed to validate and fine tune one design rather than exploring widely differing design concepts. Thus, these analyses are often performed only after a significant commitment has been made to a particular engine design. Computer-aided engineering, however, also has the potential for providing estimates of engine performance at the very onset of the engine design cycle. Such up-front estimates may then be used to lead the design process and to allow conceptually different engine designs to be quickly assessed. For instance, up-front estimates of engine vibration and forces transmitted through engine mounts would support target cascading of engine related noise and vibration requirements at the onset of the design cycle. The objective of this paper is to review the formulation of a simulation tool to support up-front engine design for noise and vibration. This tool provides estimates of important engine noise and vibration measures based only upon a conceptual engine design. Major components of the engine model include a rigid engine block, a flexible crankshaft with hydrodynamic bearings, torsional and bending modes, and nonlinear (frequency/load dependent) engine mounts. The formulation of this model is detailed herein and sample results are reviewed for one engine design.

Systematic Construction of the Equations of Motion for Multibody Systems Containing Closed Kinematic Loops

1989 ◽  
Author(s):  
P. E. Nikravesh ◽  
G. Gim
Keyword(s):  
Equations Of Motion ◽  
Transformation Matrix ◽  
Velocity Transformation ◽  
Constraint Equations ◽  
Advantages And Disadvantages ◽  
Lagrange Multiplier Technique ◽  
Joint Coordinates ◽  
Minimum Number ◽  
Kinematic Loops ◽  
Equations Of Motions

Abstract This paper presents a systematic method for deriving the minimum number of equations of motion for multibody system containing closed kinematic loops. A set of joint or natural coordinates is used to describe the configuration of the system. The constraint equations associated with the closed kinematic loops are found systematically in terms of the joint coordinates. These constraints and their corresponding elements are constructed from known block matrices representing different kinematic joints. The Jacobian matrix associated with these constraints is further used to find a velocity transformation matrix. The equations of motions are initially written in terms of the dependent joint coordinates using the Lagrange multiplier technique. Then the velocity transformation matrix is used to derive a minimum number of equations of motion in terms of a set of independent joint coordinates. An illustrative example and numerical results are presented, and the advantages and disadvantages of the method are discussed.

Effect of Forcing Terms and General Characteristics of Torsional Vibrations of Marine Engine Systems with Variable Inertia

1974 ◽  
Vol 18 (02) ◽  
pp. 131-138
Author(s):  
W. D. Carnegie ◽  
M. S. Pasricha
Keyword(s):  
Equations Of Motion ◽  
Mean Value ◽  
Wave Form ◽  
Actual System ◽  
Computer Methods ◽  
Reciprocating Engine ◽  
Complex Wave ◽  
Wave Forms ◽  
Crankshaft Rotation ◽  
Engine Systems

The torsional vibration phenomenon in the running gear of reciprocating engine systems is usually dealt with by considering a series of constant inertias connected by sections of massless shafting. Such a simplified model does not reproduce the exact dynamic characteristics of the actual system. In recent years several cases of marine crankshaft failures have been attributed to the phenomenon of secondary resonance, which is explained by the fact that the effective inertia of each slider crankmechanism varies about a mean value in relation to the position of the crank. When the variableinertia effect is allowed for, the equations of motion taking into account the effect are nonlinear. Assuming small displacements, the equations can be linearized to predict important characteristics of the motion. The motions in the form of complex wave forms are studied at different speeds of engine rotation and some of the wave form solutions are analyzed in the range of present investigations. Computer methods making use of numerical analysis processes, namely, the modifiedEuler's equations and the Runge-Kutta constants, have been applied in the investigations. A study of the effect on the motion of the system due to variation of inertia ratio is carried out at a particular speed of the crankshaft rotation; also investigated are the variations in the motions due to the action of external excitations with respect to changes in phase angle and inertia ratio. General comments on Draminsky's work in the light of the present investigations are included.

Use of Hybrid Engine Modeling for On-Board Module Performance Tracking

2005 ◽  
Author(s):  
Allan J. Volponi
Keyword(s):  
Real Time ◽  
Tracking System ◽  
Reference Level ◽  
Practical Consideration ◽  
Variable Model ◽  
Engine Model ◽  
Engine Modeling ◽  
Performance Tracking ◽  
Time Operation ◽  
Module Performance

A practical consideration for implementing a real-time on-board Module performance tracking system is the development of a high fidelity engine model capable of providing a reference level from which performance changes can be tracked. Real-time engine models made their advent with the State Variable Model (SVM) in the mid-80’s which provided a piecewise linear model that granted a reasonable representation of the engine during steady state operation and mild transients. Increased processor speeds over the next decade allowed more complex models to be considered which were combinations of linear and non-linear physics based components. While the latter may provide greater fidelity over transient operation and flight envelope excursions, it bears the limitation of potential model obsolescence as performance improvements in the form of hardware modifications, bleed and stator vane schedules alterations, cooling flow adjustments, and the like are made during an engine’s life cycle. Over time, these models may deviate enough from the actual engine being monitored that the module performance estimations are inaccurate and misleading. This paper describes an alternate approach to engine modeling by applying a hybrid engine model architecture that incorporates both physics-based and empirical components. This methodology provides a means to tune the engine model to a particular configuration as the engine development matures and furthermore, aligns the model to the particular engine being monitored to insure accurate performance tracking while not compromising real-time operation.

Investigation of Dynamics and Vibration of a Three Unit PIG in Oil and Gas Pipelines

2008 ◽  
Author(s):  
Mohammad Durali ◽  
Amir Fazeli ◽  
Mohsen Azimi
Keyword(s):  
Oil And Gas ◽  
Equations Of Motion ◽  
Design Procedure ◽  
Pressure Waves ◽  
Gas Oil ◽  
Oil Pipeline ◽  
Under Construction ◽  
Multi Body ◽  
Dynamics And Vibration ◽  
Body Dynamic

In this paper, the transient motion of a three unit intelligent Pipe Inspection Gauge (PIG) while moving across anomalies and bends inside gas/oil pipeline has been investigated. The pipeline fluid has been considered as isothermal and compressible. In addition, the pipeline itself has also been considered to be flexible. The fluid continuity and momentum equations along with the 3D multi body dynamic equations of motion of the pig comprise a system of coupled dynamic differential equations which have been solved numerically. Pig’s position and velocity profiles as well as upstream and downstream fluid’s pressure waves are presented as simulation results which provide a better understanding of the complex behavior of pig motion through pipelines. This study has been conducted as a part of the design procedure for the Pig which is currently under construction.

Investigation of Dynamics and Vibration of PIG in Oil and Gas Pipelines

2007 ◽  
Author(s):  
Mohammad Durali ◽  
Amir Fazeli ◽  
Ali Nabi
Keyword(s):  
Oil And Gas ◽  
Equations Of Motion ◽  
Design Procedure ◽  
Pressure Waves ◽  
Gas Oil ◽  
Pipe Inspection ◽  
Oil Pipeline ◽  
Oil And Gas Pipelines ◽  
Under Construction ◽  
Dynamics And Vibration

In this paper, the transient motion of an intelligent Pipe Inspection Gauge (PIG) while moving across anomalies inside a typical gas/oil pipeline has been investigated. The pipeline fluid has been considered as isothermal and compressible. In addition, the pipeline itself has also been considered to be flexible. The fluid continuity and momentum equations along with the 3D dynamic equations of motion of the pig comprise a system of coupled dynamic differential equations which have been solved numerically. Pig’s position, orientation and velocity profiles as well as upstream and downstream fluid’s pressure waves are presented as simulation results which provide a better understanding of the complex behavior of pig motion through pipelines. This study has been conducted as a part of the design procedure for the Pig which is currently under construction.

scholarly journals The Quiet Forefront

2014 ◽  
Vol 136 (08) ◽  
pp. 44-49 ◽  
Author(s):  
Jean Thilmany
Keyword(s):  
Computer Aided Design ◽  
Consumer Electronics ◽  
Element Analysis ◽  
Design Engineers ◽  
Acoustical Analysis ◽  
Design Changes ◽  
Development Cycle ◽  
Design Cycle ◽  
The Many ◽  
Aided Design

This article highlights the acoustical analysis changes made by manufacturers in design cycle. Acoustical simulation is being pushed from experts to designers, following the trend for the last 15 or so years that saw other types of engineering applications like finite element analysis and computational fluid dynamics become integrated with computer-aided design packages used by mechanical engineers. With the advent of software packages that allow for design and for acoustical analysis in tandem, design engineers are increasingly running these analyses early in the development cycle and are making design changes to decrease noise and vibration issues they find. Experts suggest that with speaker sound quality and other pertinent information in hand, designers can actually design from the get-go with that information in mind, resulting in fewer design changes down the line. Though early acoustical simulation is still perhaps one of the consumer electronics’ industries best-kept secrets, that’s likely to change as word gets out about the many advantages of front-line simulation.

Design and Analysis of a Lightweight Polygon Engine

2013 ◽  
Author(s):  
Adam N. Clark ◽  
Kevin R. Anderson ◽  
Clifford M. Stover ◽  
Stephen L. Cunningham ◽  
Martin Stuart
Keyword(s):  
Compression Ratio ◽  
Weight Ratio ◽  
Kinematic Modeling ◽  
Gasoline Engines ◽  
Analysis And Design ◽  
Current Trends ◽  
Engine Design ◽  
Piston Speed ◽  
Engine Systems ◽  
Plane Polygon

Current trends in engine design have pushed the state-of-the-art regarding high power-to-weight ratio gasoline engines. Newly developed engine systems have a power to weight ratio near 1 hp per pound. The engine configuration presented herein makes it possible to package a large number of power producing pistons in a small volume resulting in a power to weight ratio near 2 hp per pound, which have never before been realized in a production engine. The analysis and design of a lightweight, two-stroke, 6 side, in-plane, polygon engine having a geometric compression ratio of 15.0, actual compression ratio of 8.8 and piston speed of 3500 ft/min are presented in this investigation. Power output, kinematic modeling, and weight estimates are presented.

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