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.

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.

Cycle Optimisation Using an Advanced, Real Engine Performance Prediction Model

2002 ◽  
Author(s):  
Miles Coppinger ◽  
Graham Cox ◽  
John Hannis ◽  
Nigel Cox
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
Integer Number ◽  
Turbine Engine ◽  
Engine Model ◽  
Engine Design ◽  
Industrial Gas Turbines ◽  
High Degree ◽  
Technology Level

A whole gas-turbine engine model has been developed incorporating all of the key turbomachinery aerothermal relationships. The aim of the model has been to predict trends in gas-turbine performance with a high degree of confidence that they reflect real engine design limitations. Simple cycles, recuperated, inter-cooled, and inter-cooled recuperated cycles can be assessed across a wide of range of operating parameters. The model is spreadsheet-based with additional macro programming. The major part of it is concerned with establishing representative overall turbine characteristics. A non-integer number of stages is determined as a function of technology level inputs. Individual stage geometry features are derived allowing the calculation of the coolant requirements and efficiencies. The results of various studies are presented for a number of cycle types. The resulting trends are believed to be sensible because of the realistic turbine features. Confidence in the method is established by the modelling of a number of existing industrial gas turbines.

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 Collaborative Architecture for Multiple Computer Aided Engineering Applications

2002 ◽  
Author(s):  
David Cramer ◽  
Uma Jayaram ◽  
Sankar Jayaram
Keyword(s):  
Computer Aided Engineering ◽  
Data Sets ◽  
Design Environment ◽  
Virtual Design ◽  
Engineering Applications ◽  
Data Packets ◽  
Design And Implementation ◽  
Design Cycle ◽  
Computer Aided ◽  
Exchange Data

In this paper, we describe the need, design, and implementation of a Collaborative Architecture. The Collaboration Architecture addresses the need for multiple Computer Aided Engineering applications to exchange data packets directly with each other in an effort to decrease the design cycle time. This architecture incorporates three components in its design, a server, a controller, and multiple members. The members generate and use the data packets. The server maintains and distributes the data packets between the members. The controller component determines which CAE users are generating or using which data sets. The member component has been implemented with three subcomponents, a pusher application, a receiver application, and the CAE application which uses / generates the data packets. For the local member communication, the Collaborative Architecture uses shared memory. For inter-component communication, the architecture uses CORBA. Finally, this paper describes the implementation of two Computer Aided Applications, Dv/Mockup and an Immersive Virtual Design Environment.

Prospects for Discovering the Secondary Metabolites of Cordyceps Sensu Lato by the Integrated Strategy

2020 ◽  
Vol 17 (2) ◽  
pp. 97-120
Author(s):  
Shabana Bibi ◽  
Yuan-Bing Wang ◽  
De-Xiang Tang ◽  
Mohammad Amjad Kamal ◽  
Hong Yu
Keyword(s):  
Drug Design ◽  
Biological Activities ◽  
Design Methods ◽  
Chinese Herbs ◽  
Active Metabolites ◽  
Computer Aided Drug Design ◽  
Design Concepts ◽  
Conventional Drug ◽  
Computer Aided ◽  
Design Techniques

: Some species of Cordyceps sensu lato are famous Chinese herbs with significant biological activities, often used as edible food and traditional medicine in China. Cordyceps represents the largest entomopathogenic group of fungi, including 40 genera and 1339 species in three families and incertae sedis of Hypocreales. Objective: Most of the Cordyceps-derivatives have been approved clinically for the treatment of various diseases such as diabetes, cancers, inflammation, cardiovascular, renal and neurological disorders and are used worldwide as supplements and herbal drugs, but there is still need for highly efficient Cordyceps-derived drugs for fatal diseases with approval of the U.S. Food and Drug Administration. Methods: Computer-aided drug design concepts could improve the discovery of putative Cordyceps- derived medicine within less time and low budget. The integration of computer-aided drug design methods with experimental validation has contributed to the successful discovery of novel drugs. Results: This review focused on modern taxonomy, active metabolites, and modern drug design techniques that could accelerate conventional drug design and discovery of Cordyceps s. l. Successful application of computer-aided drug design methods in Cordyceps research has been discussed. Conclusion: It has been concluded that computer-aided drug design techniques could influence the multiple target-focused drug design, because each metabolite of Cordyceps has shown significant activities for the various diseases with very few or no side effects.

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