scholarly journals Design of dynamic trajectories for efficient and data-rich exploration of flow reaction design spaces

2021 ◽  
Author(s):  
Federico Florit ◽  
Anirudh Manoj K. Nambiar ◽  
Christopher Breen ◽  
Timothy F Jamison ◽  
Klavs F Jensen
Keyword(s):  
Design Space ◽  
Operating Conditions ◽  
Transient Experiments ◽  
Chemical Design ◽  
Flow Reaction ◽  
Over Time

Batch and continuous reactors both enable exploration of a chemical design space. The former rely on transient experiments, thus experiencing a wide variety of operating conditions over time, whereas the...

scholarly journals Metrological performance of single-jet water meters over time

2018 ◽  
Vol 13 (5) ◽  
pp. 1
Author(s):  
Carmen Virginia Palau ◽  
Juan Manzano ◽  
Iban Balbastre Peralta ◽  
Benito Moreira de Azevedo ◽  
Guilherme Vieira do Bomfim
Keyword(s):  
Measurement Error ◽  
Water Consumption ◽  
Operating Conditions ◽  
Economic Losses ◽  
Flow Rates ◽  
Metrological Operation ◽  
Operation Period ◽  
Single Jet ◽  
Water Meters ◽  
Over Time

To maintain quality measurement of water consumption, it is necessary to know the metrology of single-jet water meters over time. Knowing the accuracy of these instruments over time allows establishing a metrological operation period for different flow rates. This will aid water companies to optimize management and reduce economic losses due to unaccounted water consumption. This study analyzed the influence of time on the measurement error of single-jet water meters to evaluate the deterioration of the equipment and, with that, launch the metrological operation period. According to standards 8316 and 4064 of the International Organization for Standardization (ISO), 808 meters of metrological Class B were evaluated in six water supplies, with age ranges of 3.7 to 16.4 years of use. The measurement error was estimated by comparing the volume measured in a calibrated tank with the volume registered by the meters at flow rates of 30, 120, 750 and 1,500 L h-1. The metrological operation period of the meters was obtained for each flow rate by the relation between error of measurement and time of use (simple linear regression). According to the results, the majority of the equipment presents increasing under-registration errors over time, more pronounced at low flow rates and with less favorable operating conditions. The metrological operation period for flow rates of 30, 120, 750 and 1,500 L h-1 is estimated at approximately 3, 8, 14 and 13 years. This operation period combined with consumption patterns of users will establish the best time to replace the meters.

Cycle Design Exploration Using Multi-Design Point Approach

2012 ◽  
Author(s):  
Jeffrey Schutte ◽  
Jimmy Tai ◽  
Jonathan Sands ◽  
Dimitri Mavris
Keyword(s):  
Gas Turbine ◽  
Design Space ◽  
Traditional Approach ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Feasible Region ◽  
Turbine Engine ◽  
Design Point ◽  
Performance Requirements ◽  
Design Cycle

The focus of this study is to compare the aerothermodynamic cycle design space of a gas turbine engine generated using two on-design approaches. The traditional approach uses a single design point (SDP) for on-design cycle analysis, where off-design cycle analysis must be performed at other operating conditions of interest. A multi-design point (MDP) method performs on-design cycle analysis at all operating conditions where performance requirements are specified. Effects on the topography of the cycle design space as well as the feasibility of the space are examined. The impacts that performance requirements and cycle assumptions have on the bounds and topography of the feasible space are investigated. The deficiencies of a SDP method in determining an optimum gas turbine engine will be shown for a given set of requirements. Analysis will demonstrate that the MDP method, unlike the SDP method, always obtains a properly sized engine for a set of given requirements and cycle design variables, resulting in an increased feasible region of the aerothermodynamic cycle design space from which the optimum performance engine can be obtained.

A Design Tool for Distributed Concept Development

2008 ◽  
Author(s):  
Kate Nordland ◽  
Edward Hensel
Keyword(s):  
Design Space ◽  
Concept Development ◽  
Design Tool ◽  
Design Environment ◽  
Weighted Voting ◽  
Design Intent ◽  
Morphological Chart ◽  
The Brain ◽  
Over Time

This paper provides an overview of a database tool to support collaborative concept development in an asynchronous, distributed design environment. This paper will illustrate how an ideation method, such as as brainstorming, can be applied to a desired set of functions for a new design. The result of the brain-storming session for each articulated function can then be used in conjunction with a collaborative weighted voting tool to develop a rank-ordered morphological chart of the design space. A case study will be presented to illustrate how the information and knowledge generated in a prior working session by a design group can be introduced into a subsequent design session. The case study will illustrate how knowledge can be effectively transferred from one design project to the next, and preserve design intent over time.

Robustness in Optimum Design of Freeform Mechanical Parts

2000 ◽  
Author(s):  
Dulyachot Cholaseuk ◽  
Vijay Srinivasan ◽  
Vijay Modi
Keyword(s):  
Optimum Design ◽  
Design Of Experiment ◽  
Design Space ◽  
Operating Conditions ◽  
Free Form ◽  
Design Point ◽  
Mechanical Parts ◽  
Iterative Design ◽  
Robust Designs ◽  
Successive Iteration

Abstract A method to identify robust designs of mechanical parts with free-form shapes is proposed. For each design, the geometry and operating conditions represent one design point in the design space, with noise altering the design point leading to a change in performance. A shape optimization process is conducted for each example problem. Each successive iteration during the process produces an iterative design point with the final one being the optimum design. Once the process is completed, a design of experiment approach is used to apply noise in order to generate samples around each and every iterative design point. Then a simple statistical method is utilized to analyze the samples in order to evaluate the robustness of each iterative design. The results show that an optimum design is not necessarily robust.

Prediction and Mitigation of Thermally Induced Creep Distortion in Gas Turbine Combustors

2007 ◽  
Author(s):  
Hany Rizkalla ◽  
Page Strohl ◽  
Peter Stuttaford
Keyword(s):  
Gas Turbine ◽  
Design Process ◽  
Optimal Operation ◽  
Operating Conditions ◽  
Thermal Loads ◽  
Thermally Induced ◽  
Part Load ◽  
Gas Turbine Combustors ◽  
Over Time ◽  
Load Conditions

In an effort to maximize efficiency and decrease emissions, modern gas turbine combustors are exposed to extreme operating conditions which if not accounted for during the design process, can lead to premature failure of the combustion components. Of interest to this article are some operating conditions that, in many instances can expose the gas turbine combustion chambers (liners) to asymmetric thermal loads. Highly asymmetric thermal loads at high temperatures can inflict severe distress on combustion liners attributing to thermal creep distortion and Thermo-Mechanical Fatigue (TMF). Modern low emission pre-mix combustion systems such as the Dry Low NOx (DLN) 2.6 in the GE F Class machines and PSM’s FlameSheet combustor employ firing curves that involve “staging” when the gas turbine is ramping up or down in load or is simply operating in part-load condition. During such staging process, the flame resides in only certain sectors of each combustor while the other sectors are cold, these part load conditions can cause high thermal gradients leading to high thermally induced stresses in the liners. High thermal stresses at high metal temperatures can induce severe visco-plastic (creep) geometric distortion in liners upon prolonged exposure to such conditions. Extreme thermally induced creep distortion can eventually lead to liners’ catastrophic failures due to buckling and/or rupture. Under mild circumstances permanent creep distortion of liners can lead to non-optimal combustion and hence attributing to non optimal operation of the gas turbine. Several means can be employed during the design process to avoid and/or account for creep distortion, some of which are discussed in this article. Although linear elastic analysis is usually used by design engineers to predict liner thermal deflection under part load conditions, it is important to note that even though the resulting stresses may be within the material’s elastic range, creep relaxation leading to permanent liner deformation may still occur over time causing non-optimal base load operation and degradation to the gas turbine efficiency. In most cases predicting thermally induced creep distortion over time can only be done using iterative numerical techniques such as FEA coupled with the material specimen creep testing. A case study involving a F class FlameSheet liner will be discussed and used for illustrative purposes. ANSYS non-linear creep FEA modeling was used to predict the creep deformation results over time using Haynes 230 specimen test data. The predicted numerical analytical results matched well with actual hardware characterized data, thus validating the analytical technique.

Influence of Design Parameters on the Performance of a Multistage Centrifugal Compressor for Supercritical Carbon Dioxide Applications

2015 ◽  
Author(s):  
B. Monge ◽  
D. Sánchez ◽  
M. Savill ◽  
P. Pilidis ◽  
T. Sánchez
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Centrifugal Compressor ◽  
Design Space ◽  
Operating Conditions ◽  
Design Parameters ◽  
Working Fluid ◽  
Small Scale ◽  
Main Design ◽  
Supercritical Carbon

The development of the supercritical Carbon Dioxide power cycle has relied on parallel tracks along which theoretical and experimental works have successfully complemented each other in the last few years. Following this approach, intensive work on the development of critical components has enabled the demonstration of the technology in small-scale test loops. The next step in the roadmap is scaling-up the technology in order to bridge the gap to commercialisation. To this aim, not only is it necessary to demonstrate that the cycle works, but it is also mandatory to rise component (and system) efficiencies to levels comparable with competing technologies. In this process, assessing the impact of the main design parameters on the efficiency of turbomachinery is deemed crucial. The present work is a follow-up to others presented by the authors in previous years where preliminary analysis on centrifugal compressor design combining tools of different levels of fidelity were used. Nevertheless, whilst these presented guidelines to design the main compressor successfully, this new piece of research presents how the design space of the unit is affected by the characteristics of the working fluid. A review of past research is first presented to evidence that the design space is largely influenced by the particular behaviour of the working fluid close to the critical point. Then, design maps are presented for different operating conditions (cycle heat balance), showing that their shapes change substantially depending on compressor inlet pressure and temperature. Also, a comparison of these maps confirms that the design regions enabling high efficiency can be substantially reduced depending on the inlet/outlet thermodynamic states. Finally, conclusions are drawn regarding optimal intervals for the main design parameters involved in the process.

scholarly journals Comparative analysis of foreign experience in accounting of machine and tractor fleet depreciation in agricultural organizations

2021 ◽  
pp. 83-96
Author(s):  
A. A. Efremov ◽  
I. L. Kovalev
Keyword(s):  
Comparative Analysis ◽  
Operating Conditions ◽  
Agricultural Machinery ◽  
Agricultural Enterprises ◽  
The World ◽  
Specific Factors ◽  
Conceptual Overview ◽  
Repair Cycle ◽  
Over Time

The article presents a conceptual overview of modern approaches to accounting for depreciation of machine and tractor fleet in agrarian production used in different countries of the world. The emphasis is placed on the agricultural specifics, which determines the use of certain methods and tools for calculating depreciation charges. The mechanism of the influence of the operating conditions of agricultural machinery on the choice of the organization’s depreciation policy, as well as the distinctive principles of management accounting for depreciation at agricultural enterprises, is disclosed, the possibilities of taking into account a number of specific factors in the process of determining depreciation are considered – inflation, uneven operation of equipment, its repair cycle, etc. The problem of scientifically based distribution of the value of long-term assets over time is touched upon.

scholarly journals Optimization of Francis Turbines for Variable Speed Operation Using Surrogate Modeling Approach

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Igor Iliev ◽  
Erik Os Tengs ◽  
Chirag Trivedi ◽  
Ole Gunnar Dahlhaug
Keyword(s):  
Design Space ◽  
Operating Conditions ◽  
Francis Turbine ◽  
Optimization Strategy ◽  
Variable Speed ◽  
Hydraulic Design ◽  
Speed Performance ◽  
Quadratic Response ◽  
Specific Speed ◽  
The Hill

Abstract Previous studies suggested variable speed operation (VSO) of Francis turbines as a measure to improve the efficiency at off-design operating conditions. This is, however, strongly dependent on the hydraulic design and, for an existing turbine, improvements can be expected only with a proper redesign of the hydraulic surfaces. Therefore, an optimization algorithm is proposed and applied to the runner of a low specific speed Francis turbine, with an optimization strategy specifically constructed to improve the variable speed performance. In the constrained design space of the reference turbine, the geometry of the replacement runner is parametrically defined using 15 parameters. Box–Behnken method was used to populate the design space with 421 unique samples, needed to train fully quadratic response surface models of three characteristic efficiencies defined by the proposed objective function. Computational fluid dynamics (CFD) was used to calculate the responses for each sample. The parametric study showed that the anticipated variation of the shape of the hill chart, needed to improve the variable speed performance of the turbine, is limited within a narrow range. The presented method is general and can be applied to any specific speed in the Francis turbine range, for both synchronous speed and variable speed optimization tasks.

scholarly journals Understanding the Diversity of the Metal-Organic Framework Ecosystem

2020 ◽  
Author(s):  
Seyed Mohamad Moosavi ◽  
Aditya Nandy ◽  
Kevin Maik Jablonka ◽  
Daniele Ongari ◽  
Jon Paul Janet ◽  
...  
Keyword(s):  
Design Space ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Small Variation ◽  
Chemical Diversity ◽  
Pore Geometry ◽  
Existing Structures ◽  
New Information ◽  
Chemical Design ◽  
Metal Organic

By combining metal nodes and organic linkers one can make millions of different metal-organic frameworks (MOFs). At present over 90,000 MOFs have been synthesized and there are databases with over 500,000 predicted structures. This raises the question whether a new experimental or predicted structure adds new information. For MOF-chemists the chemical design space is a combination of pore geometry, metal nodes, organic linkers, and functional groups, but at present we do not have a formalism to quantify optimal coverage of chemical design space. In this work, we show how machine learning can be used to quantify similarities of MOFs. This quantification allows us to use techniques from ecology to analyse the chemical diversity of these materials in terms of diversity metrics. In particular, we show that this diversity analysis can identify biases in the databases, and how such bias can lead to incorrect conclusions. This formalism provides us with a simple and powerful practical guideline to see whether a set of new structures will have the potential for new insights, or constitute a relatively small variation of existing structures.

Generative Design and Topology Optimization of Disk Brake Floating Carrier

2020 ◽  
Author(s):  
Filippo Colombo Zefinetti ◽  
Daniele Regazzoni ◽  
Marco Rossoni
Keyword(s):  
Topology Optimization ◽  
Laser Scanning ◽  
Design Space ◽  
Initial Conditions ◽  
Optimization Techniques ◽  
Operating Conditions ◽  
Generative Design ◽  
Common Solution ◽  
Disk Brake ◽  
And Topology

Abstract In the last past years, computer-aided technologies to improve existing products by widening the design space have been largely investigated. Topology optimization and generative design are two of the most representative technologies of such kind. This paper aims at investigating the use of generative design and topology optimization techniques to improve products whose design has not changed radically over the years. The product under investigation is a disk brake floating caliper that is the most common solution for commercial vehicles. In general, increasing the stiffness of the floating caliper while keeping its weight under control is desirable both from performance and fuel consumption point of view. The solution here proposed aims at exploiting two new ways to approach the engineering design process and evaluate which one is more suitable for problems of this kind. Starting from the original carrier shape, acquired with laser scanning, the two technologies have been applied on the same initial conditions. The initial design space volume corresponds to the acquired shape, the loads and the constraints for the simulation have been drawn reasonably to resemble the actual operating conditions. Keeping the input parameters constants, two different off-the-shelf software packages have been used to perform the computation and with the objective of maximizing the stiffness of the carrier while reducing its mass. The comparison and the improvements on the final designs have been drawn taken as reference to the original caliper.

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