Sensitive Design Parameters Research Articles

Performance sensitivity analysis and aerodynamic optimization of compressor cascades by a turbulence adjoint method

Sensitivity, which is useful for evaluating the contributions of input variations to output changes, favors designers exploiting the most sensitive design parameters and completing design optimization in aerospace. This study introduces the turbulence adjoint method due to its low computational cost in calculating sensitivities with high accuracy and then solves the adjoint partial differential equations with respect to both the Reynolds-averaged Navier–Stokes and turbulence model equations with the assistance of an automatic differentiation tool. By utilizing the turbulence adjoint method, the sensitivities of aerodynamic performance to the blade profile modifications of two-dimensional and three-dimensional compressor cascades are calculated, allowing for the investigations of the impact of geometric variations on the changes in the flow field. Ultimately, aerodynamic optimization of the compressor cascades is conducted. After optimization, the adiabatic efficiency of the two-dimensional cascade increases by 3.11%, and it increases by 1.15% for the three-dimensional cascade. The variations in flow fields of both the original and optimized cascades are illustrated to discover the origins of performance improvements. The changes in blade profile are almost consistent with those forecasted from sensitivity analysis, demonstrating the potential superiority of the adjoint method for aerodynamic design.

Evaluation of the fiber optic curvature sensor design parameters for new measurement approach application

In this paper, the influence of sensitive zone design parameters on the performance of fiber optic curvature sensor (FOCS) with sensitive zone made of V-grooves is experimentally investigated. A new insight into FOCS operation is given by introducing optical mode converter and CCD sensor into experimental setup, thus enabling mode-dependent analysis of V-grooves depth and spacing influence on sensor sensitivity and providing increased measurement reliability. Based on experimental analysis conducted in this work it is shown that FOCS intensity sensitivity increases approximately linear with sensitive zone depth and length, with highest sensitivity obtained for low order modes. According to this mode-dependent analysis, a new and more reliable measurement approach based on measurement of changes in the width of the output light distribution, rather than intensity, is proposed and tested. FOCS FWHM sensitivity increases approximately linear with depth and length of the sensitive zone, with higher sensitivity obtained in case of convex deformation. However, better linearity and balanced FWHM response is obtained for lower depths and shorter lengths of sensitive zone.

Hydrogen storage systems performance and design parameters using response surface methods and sensitivity analysis

DesignDesign of metal hydride-based hydrogen storage reactors is often performed using numerical/experimental modelling which is computationally/economically difficult. This paper investigates the applicability of Response Surface Methodology (RSM) coupled Local/Global Sensitivity Analysis (L/GSA) to investigate – i) the applicability of advanced RSMs in predicting the responses for storage systems efficiently, ii) the applicability of advanced RSMs to perform L/GSA to identify the sensitive input design parameters based on their effect on the Outputs of Interests (OIs), i.e., reaction fraction (i.e., C) and bed temperature (i.e., T), and iii) the dependence of importance ranking of design parameters on the employed L/GSA methodology. The study is conducted in two stages. In the first stage, the most accurate RSM was identified among fourteen traditional and advanced RSMs, i.e., radial basis, kriging, quadratic, moving least square, support vector machine etc., employing a measure of precision, i.e., Nash–Sutcliffe Efficiency (NSE). RSMs were constructed based on the values of OIs estimated using finite element simulation using COMSOL software for random realizations of inputs generated via Latin Hypercube Sampling (LHS). In the second stage, the importance ranking of design parameters was estimated for both OIs using six different L/GSAs based on the input-output relationships estimated in stage one. All the codes of RSMs and L/GSAs were written and validated in MATLAB. Finite element simulations of the random realizations were performed using COMSOL software. For the present study, NSEs of the considered RSMs were ranging between 0.6262-0.8544 and 0.4652–0.8081 for C and T respectively, indicating the importance of selection of appropriate RSM. RBF-augmented Compact-I and kriging were the most accurate RSMs with NSEs approximately 10%–20 % higher to those of frequently used polynomial RSM. Time (t) and mass of hydrogen to be stored (MH) were the most; and external temperature (Text) and porosity (E) were the least sensitive inputs corresponding to C and T, with differences of 80–90 % in the sensitivity indices respectively. The ranking prediction was highly dependent upon the employed L/GSA methodology, with Morris's screening observed to be the least accurate. The RSM methods described in this study help to design and investigate the metal hydride reactors for various applications (space heating, hydrogen storage, storage for vehicular application, metal hydride compressor) without undergoing detailed mathematical modelling of the system. The proposed methodology may significantly assist the designers to focus (or vary) on the sensitive inputs only during the physical modelling of systems to improve their performance. This sensitivity analysis is helpful to find out the most advance sensitivity analysis method which can be used to find out the most sensitivity parameter which can be varied according to their rankings to achieve the required performance of metal hydride reactor for the particular application. The advanced RSMs assist to identify these sensitive inputs quickly by reducing the mathematical efforts in the L/GSA by providing the accurate input-OIs relationships based on the limited numerical simulations. This will significantly save the resources and time of industries required in physical modelling/numerical simulations significantly, which otherwise would have been invested on investigating the non-sensitive inputs.

On the design of vehicle front-ends for pedestrian safety with the advanced Pedestrian Legform Impactor (aPLI)

The latest Euro NCAP Vulnerable Road Users Assessment Protocol (v11.3) introduces the advanced Pedestrian Legform Impactor (aPLI) to reduce the risk of lower extremity injury to pedestrians in a vehicle collision. The addition of femur injury criteria and the added simplified upper body mass, compared to its predecessor –the FlexPLI–, allows a more comprehensive assessment of passive pedestrian safety. However, this presents new challenges for vehicle manufacturers as these additions must be accounted for. We perform four sensitivity analyses at two test positions (centre and at the headlight) on two vehicles (compact car and SUV). Thereby, we investigate five design parameters that represent the main front-end components and identify that the vehicle type determines the sensitive design parameters significantly. Furthermore, we show that the influence of the lower stiffener and energy-absorbing foam diminishes compared to older legform impactors, while that of the bonnet increases.

Unit-scale- and catchment-scale-based sensitivity analysis of bioretention cell for urban stormwater system management

Abstract An improved understanding of bioretention cell (BC) design configuration at both the unit scale and catchment scale is necessary for critical insight into dynamical behaviors of design parameters, which resultantly guides and improves the effectiveness and efficiency of a BC. A comprehensive sensitivity analysis (SA) of BC design parameters was conducted in this study by using the Stormwater Management Model (SWMM) which is globally used for BC's modeling. The preliminary screening of various design parameters is conducted by the one-factor-at-a-time (OAT) SA method and the key influential parameters (i.e., conductivity, berm height, vegetation volume, suction head, porosity, wilting point, and soil thickness) are selected for further SA. To this end, 1,000 random uniformly distributed samples of each sensitive design parameter are simulated by a Python wrapper of SWMM (PySWMM) under different design storms at the unit scale and catchment scale, respectively. Unit-scale SA results found unique characteristics of each design parameter under different storm scenarios, and their behaviors toward different model responses dynamically change within their factor spaces. Catchment-scale SA results conclude vegetation and soil layers design parameters have significant impacts on controlling stormwater at the catchment scale, and optimal selection of design parameters of vegetation (type, density, and height) and soil (type, layer thickness, and void ratio) is necessary for significantly improving the effectiveness of the BC at the catchment scale.

Understanding the Early Stage of Planet Formation: Design and Demonstration of the Space Experimental Apparatus

Planet formation begins with the collision and growth of dust in protoplanetary disks. Concerning the basic cognition of the early stage of planet formation, a long-standing weakness of the research is a comprehensive physical model describing the collisional evolution of dust particles. Microgravity experiments providing original data are crucial in developing related theories. In this work, we propose an experimental scheme for observing the collisional growth of dust analogues under a unidirectional and continuous shearing process, aiming at a future implementation in space experiments. The experimental process is simulated using the discrete element method, and the atlas of the design parameter versus the evolutionary path is depicted. We notice fractal structures and growth stalling as remarkable outcomes in the process of collisional growth, which is analogous to the evolutionary mechanism in the ancient protoplanetary disks. Based on these phenomena, we determine the sensitive design parameters, i.e., the shear velocity and the filling factor, which serve as the recommended parameters in future space experiments. The validation using numerical experiments shows that the experimental scheme with proper design parameters is feasible, which promises to generate constructive data that will facilitate the development of planet formation theory.

Global sensitivity analysis and optimisation of design parameters for low GHG emission lifecycle of multifamily buildings in India

In India, nearly 25% of citizens live in slums, unfit for a decent living. Replacing the existing residential building stock and the rapid development of the economy will significantly increase energy consumption and related greenhouse gases (GHG) emissions in the coming decades. Consequently, there is a high need of developing low lifecycle GHG emission, affordable and comfortable multifamily building designs, which can be widely implemented in the Indian construction market.The objective of this article is first to explore the most influential design parameters of the multifamily building located in the in: warm and humid (Bhubaneswar), hot and dry (Jodhpur), and composite (New-Delhi) climate zones of India on life cycle GHG emissions and indoor thermal comfort, and secondly, to perform a multi-objective optimisation considering the life cycle GHG emissions, life cycle cost and initial material investment cost based on the set of the most sensitive design parameters. The study combines a two-step global sensitivity analysis based on the Morris and Fast method with a multi-objective genetic algorithm integrated into one framework based on the parametric multifamily building model with extensive building performance simulations.The global sensitivity analysis results indicated that for all investigated locations: the apartment’s floor area, equipment load, windows-to floor ratio, mechanical ventilation airflow, and cooling temperature setpoint were the most influential design parameters in relation to the lifecycle GHG emissions. Finally, based on the multi-objective optimization, significant reductions in the range of 62–75% in terms of life cycle GHG emissions and 40–54% in terms of life cycle cost were achieved compared to the baseline 7-storey multifamily design scenario based on the minimum requirements of the Indian energy conservation code. At the same time, the initial material investment cost was 25–34% higher. The optimal set of the design strategies, resulting in the lowest life cycle GHG emissions and life cycle cost was found to be minimisation of the apartment’s floor area and windows to floor ratio, maximisation of the on-site renewable energy use, and design of a mechanical ventilation system combined with ceiling fans thus enabling the energy-efficient and thermally comfortable operation of the multifamily building with a high cooling temperature setpoint.

Climate adaptation of design scheme for energy-conserving high-rise buildings—Comparative study of achieving building sustainability in different climate scenarios

Given the climate-sensitive interactions between buildings and the immediate environment, an insight into the impact of design parameters on building energy performance under specific climate environments is crucial for the sustainable development of green buildings. The following study imparts a distinctive view of the performance-based effect of architectural and engineering design parameters on high-rise office buildings by exploiting the advantages of climatic features in different climate environments. Therewith, the study identifies and compares the major sensitive design parameters on the energy performance of high-rise buildings in different climate contexts. Furthermore, the most applicable passive strategies to attaining stipulated building sustainability criteria are established. The results indicate that the energy performance in a certain climate environment is highly sensitive to the design characteristics, such as plan ratio, core position and atrium effect. In a cold climate environment, a high-rise building with a rectangular building plan (plan ratio = 1:1.44, with vertical split-core in the absence of an atrium), satisfies the Passivhaus engineering criteria on air-tightness and fabric insulation; and adopts double-glass curtain walls, presented the best energy performance. Whereas, a square building plan (with vertical split-core and no atrium) that complies with the air-tightness and fabric insulation criteria under Passivhaus engineering standards, minimizes east- and west-bound window exposures, and adopts double-glass curtain walls exhibited the best energy performance in the hot climate zone. However, it requires renewable energy systems as an additional energy source to attain the stipulated building sustainability criteria.

Experimental and numerical approach for characterization and performance evaluation of cryogenic turboexpander under rotating condition

A small-scale radial expansion turbine is distinguished by its ease of production, higher efficiency, and reliability. Such turbines have been successfully used in cryogenic turboexpander systems for refrigeration and liquefaction of the process gas. This paper presents a methodology for design optimization, numerical, and experimental investigation of a radial turbine and nozzle (turboexpander), the most necessary and extortionate component of a nitrogen liquefaction system based on Claude cycle. The initial investigation starts with the preliminary design of a turboexpander using an in-house developed Matlab® code. Then, a Sobol method-based optimization approach has been proposed to determine the normalized sensitivity index and optimal range of major non-dimensional and geometrical variables for the better off-design performance of the turboexpander. After that, different losses of the turbine have been determined using an optimum set of loss correlations which is incorporated into the preliminary design process. This approach can overcome the optimization issues caused by the high sensitive design parameters, which may not be addressed through conventional methods, and ameliorates the off-design performance of the turboexpander (improves power output, total-to-static efficiency, and diminishing the turbine losses by 14.28%, 3.89%, and 9.61% respectively) as compared to the initial design. Based on this, three turboexpander systems are designed and a comparative numerical study has been conducted to study the flow field phenomenon and their thermodynamic performance at three operating pressure and cryogenic temperature (16 bar & 150 K, 8 bar & 120 K, and 4.5 bar & 95 K) using ANSYS CFX®. Finally, the Claude cycle-based experimental facility has been established to determine the thermal performance of the turboexpander at various operating pressure (16 and 8 bar), rotational speeds (120,612, 102,419, and 80,914 rpm), inlet temperatures (150 and 120 K), and mass flow rates (0.01–0.10 kg/s). The results illustrate that the predicted performance from the numerical simulation shows good agreement with the experimental results. Additionally, error analysis of experimental parameters has also been discussed.

Technoeconomic Assessment of LNG-Fueled Solid Oxide Fuel Cells in Small Island Systems: The Patmos Island Case Study

Liquefied natural gas (LNG) is regarded as the cleanest among fossil fuels due to its lower environmental impact. In power plants, it emits 50–60% less carbon dioxide into the atmosphere compared to regular oil or coal-fired plants. As the demand for a lower environmental footprint is increasing, fuel cells powered by LNG are starting to appear as a promising technology, especially suitable for off-grid applications, since they can supply both electricity and heating. This article presents a techno-economic assessment for an integrated system consisting of a solid oxide fuel cell (SOFC) stack and a micro gas turbine (MGT) fueled by LNG, that feeds the waste heat to a multi-effect desalination system (MED) on the Greek island of Patmos. The partial or total replacement of the diesel engines on the non-interconnected island of Patmos with SOFC systems is investigated. The optimal system implementation is analyzed through a multi-stage approach that includes dynamic computational analysis, techno-economic evaluation of different scenarios using financial analysis and literature data, and analysis of the environmental and social impact on the island. Specific economic indicators such as payback, net present value, and internal rate of return were used to verify the economic feasibility of this system. Early results indicate that the most sensitive and important design parameter in the system is fuel cell capital cost, which has a significant effect on the balance between investment cost and repayment years. The results of this study also indicate that energy production with an LNG-fueled SOFC system is a promising solution for non-interconnected Greek islands, as an intermediate carrier prior to the long-term target of a CO₂-free economy.

Improvement in the accuracy of the dynamic behaviour prediction of a bolted structure using a simplified finite element model and model updating

Bolted joints in assembled structures contribute to the dynamic behaviour of the structures but also increase uncertainties in modelling and prediction of the dynamic behaviour. This paper presents a modelling scheme able to reduce uncertainties and increase the accuracy of the prediction. A finite element (FE) model of a bolted joint structure was developed using CBUSH, CBEAM and 3D elements representing the bolts, contacting interfaces, and structural components, respectively. Normal modes analysis was performed on the FE model to calculate the natural frequencies and mode shapes. Sensitivity analysis was formulated and used in identifying the highly sensitive design parameters of the FE model. Model updating was adopted in correlating the FE model with experimental modal analysis (EMA) and producing an updated FE model. It was found that the updated FE model is capable of predicting the dynamic behaviour of the bolted joint structure with 95 per cent accuracy. This proposed scheme demonstrated potential for applicability to the dynamic behaviour analysis of complex bolted structures.

A systematic design optimization approach for interior permanent magnet machines equipped with novel semi-overlapping windings

In this paper, a systematic approach to achieve optimized design of interior permanent magnet machine (IPM) having novel semi-overlapping windings (NSWs) is presented. The optimization parameters have been determined individually by performing sensitivity analyses. Multi-objective global optimization is subsequently performed. Genetic algorithm (GA) approach, which is also known as “random search with learning algorithm” and an effective optimization tool used for design optimization of electric machines, is employed. IPMs equipped with integer-slot distributed winding (ISDW) and NSW are initially designed by using the geometric and operating parameters of Toyota Prius 2010 IPM. Subsequently, a time-stepping 2D finite element analysis (FEA)-based program is employed to perform the optimization and quickly evaluate the optimal solution among the thousands of design candidates thanks to the sensitivity analyses. In order to reveal the effectiveness and rapidity of the multi-objective global optimization, a comprehensive electromagnetic performance comparison between the original (with ISDWs), initial and optimal designs (with NSWs) is presented. Finally, a small IPM prototype globally optimized by using the proposed procedure is manufactured, and the FEA results have been validated by measurements. Our goals in this study is to advance the state of the art in the multi-objective design optimization of NSW IPMs by performing sensitivity analyses to reach the optimal solution quickly and to determine the most sensitive design parameters affecting the key performance characteristics.

Effectiveness of passive design strategies in responding to future climate change for residential buildings in hot and humid Hong Kong

The application of passive design strategies is crucial at the early architectural design stage for building energy use minimization. However, the time-varying effectiveness of passive design strategies in responding to future climate change in hot and humid climates are rather limited in the literature. This paper aims to examine the dynamic effectiveness of passive design strategies for residential buildings in Hong Kong under the context of future climate change. Using the newly developed hourly weather data and adaptive comfort standard model, the dynamic effectiveness of viable passive design strategies for residential buildings are evaluated over time in the 21st century by plotting Givoni building bio-climatic charts (BBCC) and simulation-based sensitivity analyses in a validated EnergyPlus model. Results show that solar protection strategies are still the highly sensitive strategies for building energy performance and the effectiveness of external windows’ airtightness is expected to increase up to 329% by the end of this century, whereas the cooling potential of ventilation utilization will significantly decrease over time. When the different combination of sensitive passive design parameters is implemented onto the baseline residential building model for different climate scenarios, the annual and peak cooling load can be reduced up to 56.7% and 64.5%, respectively.

Base Instability Triggered by Hydraulic Uplift of Pit-in-Pit Braced Excavations in Soft Clay Overlying a Confined Aquifer

The aim of this study is to investigate the coupling effects of re-excavation and hydraulic uplift on base instability of pit-in-pit (PIP) braced excavations. The numerical model of PIP braced excavation in Shanghai soft clay overlying a confined aquifer was established by upper-bound finite element limit analysis (UBFELA) method. The effects of the sensitive design parameters (i.e., the artesian pressure, thickness and undrained shear strength of the aquitard and excavation width of inner pit) on failure mechanisms and upper-bound safety factor (FS) against hydraulic uplift were analyzed. The results show that the value of FS increases with an increase in the thickness and undrained shear strength of the aquitard, but decreases with increasing the artesian pressure and excavation width of inner pit. The failure modes can be typically classified into three categories: circular slip surface in outer pit (M1), hydraulic uplift combined with circular slip surface in entire PIP system (M2), and basal hydraulic uplift in inner pit (M3); then the corresponding critical artesian pressure is determined. Finally, the average value of critical artesian pressure used to distinguish the three types of failure modes is recommended as the design value against hydraulic uplift in the PIP system, and validity is verified by the comparison with the current design methods. The proposed stability design by UBFELA contributes to ensure the serviceability and performance of PIP system.

Design and Optimization of a Flux-Modulated Permanent Magnet Motor Based on an Airgap-Harmonic-Orientated Design Methodology

In this article, an airgap-harmonic-orientated design method is proposed, where the airgap harmonics are newly acted as the effective bridge between the three key elements of permanent magnet sources, modulators, or armature windings and the motor performances. In the proposed design method, the airgap harmonics play couple roles of design objectives and variables, which are not only served as the design variables for the motor performances, but also considered as the objectives for design parameters. For extensive investigation, a V-shape flux-modulated permanent-magnet (V-FMPM) motor is selected as a design example, which has a potential application for the electrical vehicles. In the optimization process, the sensitivity analysis of different airgap harmonics on the torque performance is conducted to select the leading airgap harmonics. Meanwhile, the sensitivity degrees of the design parameters on the leading harmonics are calculated to pick out the sensitive design parameters. Then, the performances of the V-FMPM motor are evaluated for validating airgap-harmonic-orientated design method. Finally, a prototype motor is built and tested. Both the theoretical analysis and experimental results verify the effectiveness and reasonability of the proposed design method and the V-FMPM motor.

Acoustics design sensitivity analysis for the noise optimization of landing gears

This paper provides a new Acoustic Design Sensitivity (ADS) method for the minimization of noise on landing gear parts. The idea consists of direct differentiation of the closed-forms expressions of the acoustic pressure levels with respect to the landing gear design parameters. The outlines of the method are presented herein by considering semi-empirical formulations proposed for the acoustic pressure level but can be straightforwardly applied to other acoustics weak integral formulations or analogies. Indeed, the estimates of the noise level derivatives allow assessment of the most acoustically sensitive design parameters. Numerical implementation of the ADS method has been performed using SCILAB open code and validated by comparing with the derivatives calculated using Finite Difference Methods (FDM). Then, the sensitivity estimates have been used to minimize different (SPL and OASPL) noise objectives for a generic landing gear. The numerical examples clearly demonstrated the ability of the (ADS) method to accurately identify the appropriate design parameters that will control the bulk of the noise sensitivity. In addition, the optimum solution of the noise minimization problems is exclusively dependent on these design parameters.

Statistical Analysis of Window Impacts on Cooling and Heating Energy Use in Single Family Residence Based on Climate Regions in U.S.A.

Purpose : Window area, location, and selection of glazing are a very important factor in reducing cooling and heating energy use of a building. The primary goal of this research is to investigate the effects of window design variables on annual cooling and heating energy use in a single residence based on climate regions in the United States using statistical analysis. Method : The methodologies used in this paper are building energy simulations, descriptive statistics, t-test, Latin Hypercube Sampling, and sensitivity analysis. Two groups of window variables are defined and simulated to explore the difference of the simulation results using Latin Hypercube Sampling and t-test. Then, the enter method as a regression model is used to investigate which group of data better predicted annual cooling and heating energy use. Lastly, Standard Regression Coefficients (SRCs) sensitivity indicator is used to determine if the influence of window parameters on cooling and heating energy use varies by different climate zone. Results : T-test results show that the differences in simulation results between the two groups are not statistically significant. That means that simulations using less number of variables (Group B) can have similar accuracy than simulation with higher number of window variables (Group A). As a result of the regression models, average adjusted R2 is 0.886 for Group A and 0.933 for Group B. Therefore, the regression model using Group B is selected to determine the effect of each variable on energy use. According to SRCs from regression, the most sensitive design parameters for cooling energy use are SHGC, west and south facing windows, while U-value, north and west facing windows are the most sensitive window parameters for heating energy use.

Dynamic Analysis of Linke Hofmann Busch Coach and Determination of its Sensitive Design Parameters Considering Suspended Equipments

This study aims at dynamic behaviour of a Linke Hofmann Busch coach and its sensitive parameters against track irregularities considering various suspended equipment. The randomly distributed track irregularities characterized in terms of Indian Rail Road PSD standard are considered main source of excitation that produces undesired vibrations. The coach body and bogie frame subjected to 4 degree of freedom motions (bounce, lateral, roll and pitch) are modelled using finite element methodology where system matrices such as mass, stiffness and damping matrices are obtained for eigenvalue solution. Using modal parameters obtained as above and PSD of track irregularities, both vertical and lateral mean square acceleration responses (MSAR) are determined at various points of concern on coach body. It is observed that the vertical peak responses occur in low frequency range (0-10 Hz) which is caused by long wavelength irregularities of track that causes discomfort. It is also observed that constant peak lateral responses occur at still lower frequency as compared to vertical response which again causes discomfort to vehicle riders. This concludes that there is a further scope of improvement in comfort level with minor adjustments of suspended equipment of a LHB coach. A sensitivity analysis based on the partial derivatives against FRF displacement is conducted and most sensitive design parameters are obtained for optimization to improve ride comfort. It is suggested that if the mass of bio toilet tanks and relative position of battery box + transformer unit i.e. most sensitive parameters of suspended equipment are changed then the ride comfort can be improved

Energy modeling of urban informal settlement redevelopment: Exploring design parameters for optimal thermal comfort in Dharavi, Mumbai, India

Cities are of paramount importance to meeting our sustainable energy goals. In particular, the massive informal settlement or “slum” redevelopment programs occurring in many global cities of the developing world represent an incredible opportunity to design dwellings that improve living conditions while putting us on a trajectory towards more energy efficient cities. However, we currently lack an understanding of how redevelopment designs will impact occupant aspects like thermal comfort and energy usage. In this paper, we explore how early-stage design decisions for redevelopment of informal settlements would impact thermal comfort and energy implications in a highly contextualized energy simulation. Specifically, we conduct a first-of-its-kind analysis of the Dharavi informal settlement in Mumbai, India that identifies optimal redevelopment design configurations, explores spatial and temporal thermal heterogeneity and quantifies the impact that specific design parameters have on thermal comfort. In doing so, we aim to establish a novel computational energy modeling framework for exploring the impact that localized design parameters have on informal settlement redevelopment in India and the rest of the world. We model and simulate 18,900 design scenarios in the existing horizontal (M1) and two proposed vertical (M2, M3) building morphologies. Our results indicate that redevelopment plans must be designed carefully since simply replicating current materials and other parameters in a vertical form will likely worsen thermal comfort and associated energy burdens for occupants. Moreover, results revealed that the M3 vertical morphology was the most desired design case as it provided the most “compliant” days (i.e., days in which no dwelling exceeded the upper bound of Indian comfort standards) but thermal comfort equity could be an issue as significant variation exists between units at the ground floor and top floor. The M3 vertical morphology was also found to be the most sensitive form to other building design parameters (e.g., WWR, thermal insulation, ventilation) – underscoring the need for specific design guidelines on other parameters when adopting this form. Deeper sensitivity analysis revealed that window-to-wall ratio (WWR) was the most sensitive design parameter. Additionally, we found that the ventilation rate had as much of an impact on thermal comfort as other design parameters pointing to opportunities to enhance thermal comfort in the operational phase of dwellings. In the end, by establishing a computational energy modeling framework specifically for informal settlements and exploring design parameters for the largest informal settlement in Asia (Dharavi), our work has significant implications for how we can inform informal settlement redevelopment that both enhances occupant living conditions and set our cities’ on a pathway to a sustainable energy future.

Time-dependent concurrent reliability-based design optimization integrating experiment-based model validation

This paper presents new time-dependent concurrent reliability-based design optimization methods for improving the confidence of design results with reduced experimental cost and increased computational efficiency. The sensitive time-dependent design parameters are first selected through the developed functional Analysis of Variance. The sensitive design parameters are then validated by constructing the experimental error function based on experimental data, and the function of the mean between experiments and computer models. The sub-domains are next determined, and the time-dependent concurrent reliability-based design optimization is finally constructed and solved based on the MCS method. A case study is used to illustrate and testify our proposed methods.