Sensitivity Analysis of Aviation Environmental Impacts for the Base of Aircraft Data (BADA) Family 4

2021 ◽  
Author(s):  
Zhenyu Gao ◽  
Yongchang Li ◽  
Michelle Kirby ◽  
Dimitri N. Mavris
Keyword(s):  
Sensitivity Analysis ◽  
Environmental Impacts ◽  
Aircraft Data

scholarly journals Variance-based global sensitivity analysis and beyond in life cycle assessment: an application to geothermal heating networks

2021 ◽  
Author(s):  
Marc Jaxa-Rozen ◽  
Astu Sam Pratiwi ◽  
Evelina Trutnevyte
Keyword(s):  
Sensitivity Analysis ◽  
Life Cycle Assessment ◽  
Environmental Impacts ◽  
Spectral Clustering ◽  
Global Sensitivity Analysis ◽  
Sobol Indices ◽  
Global Sensitivity ◽  
Geothermal Heating ◽  
Trade Offs ◽  
Heating Networks

Abstract Purpose Global sensitivity analysis increasingly replaces manual sensitivity analysis in life cycle assessment (LCA). Variance-based global sensitivity analysis identifies influential uncertain model input parameters by estimating so-called Sobol indices that represent each parameter’s contribution to the variance in model output. However, this technique can potentially be unreliable when analyzing non-normal model outputs, and it does not inform analysts about specific values of the model input or output that may be decision-relevant. We demonstrate three emerging methods that build on variance-based global sensitivity analysis and that can provide new insights on uncertainty in typical LCA applications that present non-normal output distributions, trade-offs between environmental impacts, and interactions between model inputs. Methods To identify influential model inputs, trade-offs, and decision-relevant interactions, we implement techniques for distribution-based global sensitivity analysis (PAWN technique), spectral clustering, and scenario discovery (patient rule induction method: PRIM). We choose these techniques because they are applicable with generic Monte Carlo sampling and common LCA software. We compare these techniques with variance-based Sobol indices, using a previously published LCA case study of geothermal heating networks. We assess eight environmental impacts under uncertainty for three design alternatives, spanning different geothermal production temperatures and heating network configurations. Results In the application case on geothermal heating networks, PAWN distribution-based sensitivity indices generally identify influential model parameters consistently with Sobol indices. However, some discrepancies highlight the potentially misleading interpretation of Sobol indices on the non-normal distributions obtained in our analysis, where variance may not meaningfully describe uncertainty. Spectral clustering highlights groups of model results that present different trade-offs between environmental impacts. Compared to second-order Sobol interaction indices, PRIM then provides more precise information regarding the combinations of input values associated with these different groups of calculated impacts. PAWN indices, spectral clustering, and PRIM have a computational advantage because they yield stable results at relatively small sample sizes (n = 12,000), unlike Sobol indices (n = 100,000 for second-order indices). Conclusions We recommend adding these new techniques to global sensitivity analysis in LCA as they give more precise as well as additional insights on uncertainty regardless of the distribution of the model outputs. PAWN distribution-based global sensitivity analysis provides a computationally efficient assessment of input sensitivities as compared to variance-based global sensitivity analysis. The combination of clustering and scenario discovery enables analysts to precisely identify combinations of input parameters or uncertainties associated with different outcomes of environmental impacts.

scholarly journals Influential parameters for estimating the environmental impacts of geothermal power: A global sensitivity analysis study

2021 ◽  
Vol 3 ◽  
pp. 100054
Author(s):  
Andrea Paulillo ◽  
Aleksandra Kim ◽  
Christopher Mutel ◽  
Alberto Striolo ◽  
Christian Bauer ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Environmental Impacts ◽  
Global Sensitivity Analysis ◽  
Analysis Study ◽  
Global Sensitivity ◽  
Geothermal Power ◽  
Influential Parameters

Sensitivity Analysis of Airport level Environmental Impacts to Aircraft thrust, weight, and departure procedures

2020 ◽  
Author(s):  
Ameya Behere ◽  
Dongwook Lim ◽  
Yongchang Li ◽  
Yee-Chan D. Jin ◽  
Zhenyu Gao ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Environmental Impacts

scholarly journals A Sensitivity Analysis Approach to Identify Key Environmental Performance Factors

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Xi Yu ◽  
Aicha Sekhari ◽  
Antoine Nongaillard ◽  
Abdelaziz Bouras ◽  
Suiran Yu
Keyword(s):  
Sensitivity Analysis ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Environmental Performance ◽  
Product Life Cycle ◽  
Carbon Dioxide Emission ◽  
Circuit Board ◽  
Analysis Approach ◽  
Design Parameters ◽  
Performance Factors

Life cycle assessment (LCA) is widely used in design phase to reduce the product’s environmental impacts through the whole product life cycle (PLC) during the last two decades. The traditional LCA is restricted to assessing the environmental impacts of a product and the results cannot reflect the effects of changes within the life cycle. In order to improve the quality of ecodesign, it is a growing need to develop an approach which can reflect the changes between the design parameters and product’s environmental impacts. A sensitivity analysis approach based on LCA and ecodesign is proposed in this paper. The key environmental performance factors which have significant influence on the products’ environmental impacts can be identified by analyzing the relationship between environmental impacts and the design parameters. Users without much environmental knowledge can use this approach to determine which design parameter should be first considered when (re)designing a product. A printed circuit board (PCB) case study is conducted; eight design parameters are chosen to be analyzed by our approach. The result shows that the carbon dioxide emission during the PCB manufacture is highly sensitive to the area of PCB panel.

scholarly journals Comprehensive Life Cycle Environmental Assessment of Preventive Maintenance Techniques for Asphalt Pavement

2021 ◽  
Vol 13 (9) ◽  
pp. 4887
Author(s):  
Mulian Zheng ◽  
Wang Chen ◽  
Xiaoyan Ding ◽  
Wenwu Zhang ◽  
Sixin Yu
Keyword(s):  
Sensitivity Analysis ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Preventive Maintenance ◽  
Environmental Performance ◽  
Asphalt Pavement ◽  
Maintenance Strategy ◽  
Asphalt Overlay ◽  
Maintenance Techniques ◽  
Lca Results

Preventive maintenance (PM) is regarded as the most economical maintenance strategy for asphalt pavement, but the life cycle environmental impacts (LCEI) of different PM techniques have not yet been comprehensively assessed and compared, thus hindering sustainable PM planning. This study aims to comprehensively estimate and compared the LCEI of five PM techniques then propose measures to reduce environmental impacts in PM design by using life cycle assessment (LCA), including fog seal with sand, micro-surfacing, composite seal, ultra-thin asphalt overlay, and thin asphalt overlay. Afterwards, ten kinds of LCEI categories and energy consumption of PM techniques were compared from the LCA phases, and inventory inputs perspectives, respectively. Results show that fog seal with sand and micro-surfacing can lower all LCEI scores by more than 50%. The environmental performance of five PM techniques provided by sensitivity analysis indicated that service life may not create significant impact on LCA results to some extent. Moreover, four PM combination plans were developed and compared for environmental performance, and results show that the PM plan only includes seal coat techniques that can reduce the total LCEI by 7–29% in pavement life. Increasing the frequency of seal coat techniques can make the PM plans more sustainable.

scholarly journals A method to estimate the environmental impacts from genetic change in pig production systems

2019 ◽  
Vol 25 (3) ◽  
pp. 523-537 ◽  
Author(s):  
Mathias Ottosen ◽  
Stephen G. Mackenzie ◽  
Michael Wallace ◽  
Ilias Kyriazakis
Keyword(s):  
Growth Rate ◽  
Sensitivity Analysis ◽  
Environmental Impacts ◽  
Correlation Matrix ◽  
Genetic Change ◽  
Sensitivity Analyses ◽  
Pig Production ◽  
Lipid Ratio ◽  
Standard Deviations ◽  
Energy Maintenance

Abstract Purpose The environmental impacts (EIs) of the global pig production sector are expected to increase with increasing global pork demand. Although the pig breeding industry has made significant progress over the last decades in reducing its EI, previous work has been unable to differentiate between the improvements made through management improvements from those caused by genetic change. Our study investigates the effect of altering genetic components of individual traits on the EI of pig systems. Methods An LCA model, with a functional unit of 1 kg live weight pig, was built simulating an intensive pig production system; inputs of feed and outputs of manure were adjusted according to genetic performance traits. Feed intake was simulated with an animal energy requirement model. A correlation matrix of the genetic variance and correlations of traits was pooled from data on commercial pig populations in the literature. Three sensitivity analyses were applied: one-at-a-time sensitivity analysis (OAT) used the genetic standard deviations, clusters-of-traits sensitivity analysis (COT) used the genetic standard deviations and clustering based on correlations, and the sensitivity index (SI) applied the full correlation matrix. Five EI categories were considered: global warming potential, terrestrial acidification potential, freshwater eutrophication potential, land use, and fossil resource scarcity. Results and discussion The different EI categories showed similar behaviour for each trait in the sensitivity analyses. OAT showed up to 18% change in EI relative to baseline for energy maintenance and around 3% change in EI relative to baseline for most other traits. COT grouped traits into a grower/finisher cluster (up to 17% change relative to baseline), a reproductive cluster (up to 7% change relative to baseline), and a sow robustness cluster (up to 2% change relative to baseline), all clusters including negative correlations between traits. By including genetic correlations, the SI went from being influenced by maintenance, and finisher and gilt growth rate into solely being dominated by maintenancen and protein-to-lipid ratio responsible for above 0.8 and 0.35 of the variance in EI respectively. Conclusions We developed a novel methodology for evaluating EIs of changes in correlated genetic traits in pigs. We found it was essential to include correlations in the sensitivity analysis, since the local and global sensitivity analyses were not affected to the same extend by the same traits. Further, we found that finisher growth rate, body protein-to-lipid ratio, and energy maintenance could be important in reducing EI, but mortalities and sow robustness had little effect.

scholarly journals Sensitivity Analysis of Maximum Circulation of Wake Vortex Encountered by En-Route Aircraft

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 194
Author(s):  
Jose I. Rojas ◽  
Marc Melgosa ◽  
Xavier Prats
Keyword(s):  
Sensitivity Analysis ◽  
Dissipation Rate ◽  
Wake Vortex ◽  
Load Factor ◽  
Core Radius ◽  
Operational Conditions ◽  
Initial Strength ◽  
Efficient Test ◽  
Aircraft Data ◽  
Comprehensive Study

Wake vortex encounters (WVE) can pose significant hazard for en-route aircraft. We studied the sensitivity of wake vortex (WV) circulation and decay to aircraft mass, altitude, velocity, density, time of catastrophic wake demise event, eddy dissipation rate, wing span, span-wise load factor, and WV core radius. Then, a tool was developed to compute circulations of WV generated/encountered by aircraft en-route, while disregarding unrealistic operational conditions. A comprehensive study is presented for most aircraft in the Base of Aircraft Data version 4.1 for different masses, altitudes, speeds, and separation values between generator and follower aircraft. The maximum WV circulation corresponds to A380-861 as generator: 864 and 840 m2/s at horizontal separation of 3 and 5 NM, respectively. In cruise environment, these WV may descend 1000 ft in 2.6 min and 2000 ft in 6.2 min, while retaining 74% and 49% of their initial strength, respectively. The maximum circulation of WV encountered by aircraft at horizontal separation of 3 NM from an A380-861 is 593, 726, and 745 m2/s, at FL200, FL300, and FL395, respectively. At 5 NM, the circulations decrease down to 578, 708, and 726 m2/s. Our results allow reducing WVE simulations only to critical scenarios, and thus perform more efficient test programs for computing aircraft upsets en-route.

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