Estimating Target Values in Preliminary Design: An Automotive Case Study

1999 ◽  
Author(s):  
Patricia Brackin ◽  
Jonathan Colton
Keyword(s):  
Fuel Economy ◽  
Preliminary Design ◽  
House Of Quality ◽  
Acceleration Time ◽  
Engineering Characteristics ◽  
Target Values ◽  
Percent Difference ◽  
Average Percent Difference

Abstract Estimation modules have been developed for use with the House of Quality. These estimation modules are used to predict the performance of a proposed design based on the values of the Engineering Characteristics. This, paper describes the development of modules for an automotive case study. Specifically, modules for weight, price, acceleration time, and fuel economy are given. Comparison of estimated values to actual values show an average percent difference of less than 10%.

Using Genetic Algorithms to Set Target Values for Engineering Characteristics in the House of Quality

1999 ◽  
Author(s):  
Patricia Brackin ◽  
Jonathan Colton
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Penalty Functions ◽  
Preliminary Design ◽  
Test Results ◽  
House Of Quality ◽  
Design Specifications ◽  
Engineering Characteristics ◽  
Target Values

Abstract As part of a strategy for obtaining preliminary design specifications from the House of Quality, genetic algorithms were used to generate and optimize preliminary design specifications for an automotive case study. This paper describes the House of Quality for the automotive case study. In addition, the genetic algorithm chosen, the genetic coding, the methods used for mutation and reproduction, and the fitness and penalty functions are descrobed. Methods for determining convergence are examined. Finally, test results show that the genetic algorithm produces reasonable preliminary design specifications.

Using Genetic Algorithms to Set Target Values for Engineering Characteristics in the House of Quality

2002 ◽  
Vol 2 (2) ◽  
pp. 106-114 ◽  
Author(s):  
Patricia Brackin ◽  
Jonathan S. Colton
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Penalty Functions ◽  
Preliminary Design ◽  
Test Results ◽  
House Of Quality ◽  
Design Specifications ◽  
Engineering Characteristics ◽  
Target Values

As part of a strategy for obtaining preliminary design specifications from the House of Quality, genetic algorithms are used to generate and optimize preliminary design specifications for an automotive case study. This paper describes the House of Quality for an automotive case study. In addition, the genetic algorithm chosen, the genetic coding, the methods used for mutation and reproduction, and the fitness and penalty functions are described. Methods for determining convergence are examined. Finally, test results show that the genetic algorithm produces reasonable preliminary design specifications.

scholarly journals Fuel economy assessment tool for auxiliary kite propulsion of merchant ship

2018 ◽  
pp. 5-7 ◽  
Author(s):  
Vincent Podeur ◽  
Damien Merdrignac ◽  
Morgan Behrel ◽  
Kostia Roncin ◽  
Caroline Fonti ◽  
...  
Keyword(s):  
Fuel Economy ◽  
Assessment Tool ◽  
Round Trip ◽  
Merchant Ship ◽  
Added Resistance In Waves ◽  
The Mean ◽  
The Impact ◽  
Engine Power

A tool dedicated to assess fuel economy induced by kite propulsion has been developed. To produce reliable results, computations must be performed on a period over several years, for several routes and for several ships. In order to accurately represent the impact of meteorological trends variations on the exploitability of the kite towing concept, a time domain approach of the problem has been used. This tool is based on the weather database provided by the ECMWF. Two sailing strategies can be selected for assessing the performance of the kite system. For a given kite area, the simulation can be run either at constant speed or at constant engine power. A validation has been made, showing that predicted consumption is close from in-situ measurement. It shows an underestimation of 11.9% of the mean fuel consumption mainly due to auxiliary consumption and added resistance in waves that were not taken into account. To conclude, a case study is performed on a 2200 TEU container ship equipped with an 800m² kite on a transatlantic route between Halifax and Le Havre. Round trip simulations, performed over 5 years of navigation, show that the total economy predicted is of around 12% at a speed of 16 knots and around 6.5% at a speed of 19 knots.

A Strategy for Extending the House of Quality to Obtain Preliminary Design Specifications

1999 ◽  
Author(s):  
Patricia Brackin ◽  
Jonathan Colton
Keyword(s):  
Genetic Algorithms ◽  
Automotive Industry ◽  
Test Case ◽  
Preliminary Design ◽  
House Of Quality ◽  
Design Specifications

Abstract This paper details a strategy for quantifying the House of Quality to produce preliminary design specifications. Estimation modules replace the traditional symbols in the HoQ. Genetic algorithms are used to produce and rate candidate preliminary design specifications. A test case from the automotive industry is implemented in order to test the effectiveness of the strategy. Results from the test case indicate that the strategy produces preliminary design specifications that are reasonable and consistent.

Simulation-Supported Early Stage Design Optimisation for a Case Study of Life Cycle Oriented Buildings

2019 ◽  
Vol 887 ◽  
pp. 353-360 ◽  
Author(s):  
Sören Eikemeier ◽  
Ardeshir Mahdavi ◽  
Robert Wimmer
Keyword(s):  
Life Cycle ◽  
Architectural Design ◽  
Early Stage ◽  
Preliminary Design ◽  
Design Phase ◽  
Design Optimisation ◽  
Stage Design ◽  
Simulation Based ◽  
Early Stage Design

To reduce the energy and resource consumption in the building sector this study is focusing on a design optimisation of life cycle oriented buildings. In order to optimise the performance of the buildings and in consequence also to achieve improved results for the mandatory Austrian energy certificate a simulation-based rapid design approach is used for the early stage design phase of the buildings, in particular for the architectural design of the buildings.Methods like the Window to Wall Ratio, at the very beginning of the design process, a parametric simulation with EnergyPlus or a more detailed optimisation approach with GenOpt are integrated in this study applied to example buildings. The results are showing that the method can be used in a circular approach for improving the heating demand of the Austrian energy certificate for this case study by more than 25 % compared to the preliminary design

scholarly journals Preliminary Design of a Small Unmanned Battery Powered Tailsitter

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Bo Wang ◽  
Zhongxi Hou ◽  
Zhaowei Liu ◽  
Qingyang Chen ◽  
Xiongfeng Zhu
Keyword(s):  
Energy Consumption ◽  
Design Methodology ◽  
Design Space ◽  
Preliminary Design ◽  
Wing Loading ◽  
Detailed Design ◽  
Discharge Model ◽  
Battery Discharge ◽  
Power And Energy

This paper presents a preliminary design methodology for small unmanned battery powered tailsitters. Subsystem models, including takeoff weight, power and energy consumption models, and battery discharge model, were investigated, respectively. Feasible design space was given by simulation with mission and weight constraints, while the influences of wing loading and battery ratio were analyzed. Case study was carried out according to the design process, and the results were validated by previous designs. The design methodology can be used to determine key parameters and make necessary preparations for detailed design and vehicle realization of small battery powered tailsitters.

Preliminary Design and Performance of Counter Rotating Turbines for Open Rotors: Part II — 0-D Methodology and Case Study for a 160 PAX Aircraft

2016 ◽  
Author(s):  
Pablo Bellocq ◽  
Inaki Garmendia ◽  
Jordane Legrand ◽  
Vishal Sethi
Keyword(s):  
Design Methodology ◽  
Design Space Exploration ◽  
Design Space ◽  
Space Exploration ◽  
Preliminary Design ◽  
Regulatory Constraints ◽  
Trade Offs ◽  
And Performance ◽  
The Impact

Direct Drive Open Rotors (DDORs) have the potential to significantly reduce fuel consumption and emissions relative to conventional turbofans. However, this engine architecture presents many design and operational challenges both at engine and aircraft level. At preliminary design stages, a broad design space exploration is required to identify potential optimum design regions and to understand the main trade offs of this novel engine architecture. These assessments may also aid the development process when compromises need to be performed as a consequence of design, operational or regulatory constraints. Design space exploration assessments are done with 0-D or 1-D models for computational purposes. These simplified 0-D and 1-D models have to capture the impact of the independent variation of the main design and control variables of the engine. Historically, it appears that for preliminary design studies of DDORs, Counter Rotating Turbines (CRTs) have been modelled as conventional turbines and therefore it was not possible to assess the impact of the variation of the number of stages (Nb) of the CRT and rotational speed of the propellers. Additionally, no preliminary design methodology for CRTs was found in the public domain. Part I of this two-part publication proposes a 1-D preliminary design methodology for DDOR CRTs which allows an independent definition of both parts of the CRT. A method for calculating the off-design performance of a known CRT design is also described. In Part II, a 0-D design point efficiency calculation for CRTs is proposed and verified with the 1-D methods. The 1-D and 0-D CRT models were used in an engine control and design space exploration case study of a DDOR with a 4.26m diameter an 10% clipped propeller for a 160 PAX aircraft. For this application: • the design and performance of a 20 stage CRT rotating at 860 rpm (both drums) obtained with the 1-D methods is presented. • differently from geared open rotors, negligible cruise fuel savings can be achieved by an advanced propeller control. • for rotational speeds between 750 and 880 rpm (relatively low speeds for reduced noise), 22 and 20 stages CRTs are required. • engine weight can be kept constant for different design rotational speeds by using the minimum required Nb. • for any target engine weight, TOC and cruise SFC are reduced by reducing the rotational speeds and increasing Nb (also favourable for reducing CRP noise). However additional CRT stages increase engine drag, mechanical complexity and cost.

Preliminary Design and Performance Assessment of an Underwater CAES System (UW-CAES) for Wind Power Balancing

2019 ◽  
Author(s):  
Marco Astolfi ◽  
Giulio Guandalini ◽  
Marco Belloli ◽  
Adriano Hirn ◽  
Paolo Silva ◽  
...  
Keyword(s):  
Energy Storage ◽  
Performance Assessment ◽  
Power Input ◽  
Compressed Air ◽  
Preliminary Design ◽  
Round Trip ◽  
Peak Shaving ◽  
Renewable Power ◽  
And Performance

Abstract A key approach to large renewable power management is based on implementing storage technologies, including batteries, power-to-gas and compressed air energy storage (CAES). This work presents the preliminary design and performance assessment of an innovative type of CAES, based on underwater storage volumes (UW-CAES) and intended for installation in the proximity of deep water seas or lakes. The UW-CAES works with constant hydrostatic pressure storage and variable volumes. The proposed system is adiabatic, not using any fuel to increase the air temperature before expansion; a sufficient TIT is instead obtained through a thermal energy storage system which recovers the compression heat. The system includes (i) a set of turbomachines (modular multi-stage compressor, with partial intercooling; expansion turbine); (ii) a thermal energy storage (TES) system with different temperature levels designed to recover a large fraction of the compression heat, allowing the subsequent heating of air prior to the expansion phase; (iii) an underwater modular compressed air storage, conceived as a network of rigid but open tanks lying on the seabed and allowing a variable-volume and constant pressure operation. The compressor operates at variable loads, following an oscillating renewable power input, according to strategies oriented to improve the overall system dispatchability; the expander can be designed to work either at full load, thanks to the stability of the air flow rate and of the TIT guaranteed by the thermal storage, or at variable load. The paper first discusses in detail the sizing and off-design characterization of the overall system; it is then simulated a case study where the UW-CAES is coupled to a wind farm for peak shaving and dispatchability enhancement, evaluating the impact of a realistic power input on performances and plant flexibility. Although the assessment shall be considered preliminary, it is shown that round trip efficiency in the range of 75%–80% can be obtained depending on the compressor section configuration; making the UW-CAES a promising technology compared to electrochemical and pumped-hydro storage systems. The technology is also applied to perform peak-shaving of the electricity production from a wind park; annual simulations considering part load operation result in global round trip efficiency around 75% with a 10 to 15% reduction in the average unplanned energy injection in the electric grid. The investigated case study provides an example of the potential of this system in providing power output peak shaving when coupled with an intermittent and non-predictable energy source.

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