Methodological support in sustainable engineering through data-driven design of mechatronic systems

Embedding sustainable practices into pharmaceutical R&D: what are the challenges?

We study the use of Hessian interaction terms to quickly identify design variables that reduce variability of system performance. To start we quantify the uncertainty and compute the variance decomposition to determine noise variables that contribute most, all at an initial design. Minimizing the uncertainty is next sought, though probabilistic optimization becomes computationally difficult, whether by including distribution parameters as an objective function or through robust design of experiments. Instead, we consider determining the more easily computed Hessian interaction matrix terms of the variance-contributing noise variables and the variables of any proposed design change. We also relate the Hessian term coefficients to subtractions in Sobol indices and reduction in response variance. Design variable changes that can reduce variability are thereby identified quickly as those with large Hessian terms against noise variables. Furthermore, the Jacobian terms of these design changes can indicate which design variables can shift the mean response, to maintain a desired nominal performance target. Using a combination of easily computed Hessian and Jacobian terms, design changes can be proposed to reduce variability while maintaining a targeted nominal. Lastly, we then recompute the uncertainty and variance decomposition at the more robust design configuration to verify the reduction in variability. This workflow therefore makes use of UQ/SA methods and computes design changes that reduce uncertainty with a minimal 4 runs per design change. An example is shown on a Stirling engine design where the top four variance-contributing tolerances are matched with two design changes identified through Hessian terms, and a new design found with 20% less variance.

<p>Outdoor thermal comfort is key to creating vibrant outdoor urban spaces. The built form is able to modify solar radiation and wind. However, there is currently no way of considering the effect of the built form on thermal comfort when designing a new development based on the environmental factors – wind, solar radiation, and ambient temperature. Current practice for designing outdoor thermal comfort is based on simple design guidelines, and knowledge of local wind and sun patterns. A Process for Predicting Outdoor Thermal Comfort has been developed. This predicts thermal comfort based on solar radiation, wind, and ambient temperature using The Wellington Comfort Index. The process is able to predict comfort at a single point within a proposed urban development using specialised computer programs. Through predicting how the combination of solar radiation, wind, and ambient temperature will affect comfort, improvements can be made to comfort during the design phase. The aim of this thesis project is to develop the Process for Predicting Outdoor Thermal Comfort into a Comfort Tool for use at the preliminary design stage of a development. The intended users of the tool are professionals working in urban planning and architecture, such as designers and consultants who have experience with three-dimensional modelling and simulation programs. A case study research approach was used to test The Comfort Tool’s ability to inform design changes through communicating thermal comfort across a proposed development. A range of case studies were selected with different built forms. This was to test if The Comfort Tool can predict comfort in case studies with different levels of solar radiation and wind at pedestrian level due to the variations in the built forms. This research confirmed that a tool can be developed for predicting comfort across a proposed development, which can also test proposed design changes for their success during the design phase. However, further investigation is needed to determine whether The Wellington Comfort Index can be used in other cities.</p>

A stack installation experienced vortex-induced vibrations (VIV) while in-service. The magnitude of the vibrations was severe enough that cracking in the welds at the stack bases was experienced shortly after their installation. Initially, straight strakes were placed on the stacks, based on field serviceability, per API 560. The strakes proved ineffective and it was determined that the stacks would be uninstalled for repair. During the repair process, design steps were required to reduce or eliminate the VIV experienced in-service. Due to a flaw in the initial design and the ineffectiveness of the straight strake solution, the end client required verification of any proposed design changes before their implementation. Additionally, little time was allotted for the investigation of solutions. Tuned mass dampers were initially explored for the design modification. It was determined that they could not be constructed of materials suitable for the environmental operational characteristics of the stacks. It was then agreed that aerodynamic modifications of the stacks should be explored to reduce VIV. ASME STS I specifies the design and installation of helical strakes on stacks, but does not indicate the magnitude of vibration reduction that can be expected [3]. Therefore, numerical models were used to determine if the strakes would reduce or eliminate the service vibration. A baseline analysis was first conducted to validate that the tools — a combination of computational fluid dynamics (CFD) and finite element (FE) methods — could capture the in-service behavior. To perform this analysis a CFD model was constructed of the as-built stack. Using DES methods, this model was analyzed at several wind speeds to determine the magnitude and frequency content of the VIV-forcing functions. This information was then used to perform a dynamic analysis using an FE model of the stack. This model accurately predicted the correct wind speed corresponding to VIV and the amplitude of the stack’s vibration. A second model was then constructed of a stack with helical strakes, using a novel modeling methodology. This model was analyzed over a variety of wind speeds using DES methodologies. The forcing functions predicted with the helical strake model were then used to determine the stack’s in-service response. This paper contains the complete methodologies and results associated with these analyses.

The article considers the issue of modernization of the chassis of a two-link tracked transporter by applying the electromechanical drive sections. As a prototype was selected the chassis of the tracked transporters of the DT series with a mechanical transmission, which are produced serial in the Russian Federation. The proposed hybrid power installation concept can be classified as a “parallel-successive” hybrid. The relevance of the concept is determined by the expectation of operational advantages (increase of reliability, maneuverability, controllability, cross-country ability and traction-dynamic properties of the chassis and economy), which will allow to integrate such chassis into transport systems of regions with poorly developed road network infrastructure and will allow to distribution it on difficult terrain. The proposed set of modernization measures allows us to maintain the possibility of using two-link tracked transporter on soils with low bearing capacity, on off-highway, in the climatic conditions of the Far East, Far North, Arctic and Antarctic. Modernization can be carried out in the factory using components produced in the Russian Federation and technologies developed by Russian industry. The proposed design changes expand the operational capabilities of the machine without a significant increase in mass. Technical solutions are applicable when creating multi-link machines.

DOE is developing a new generation of radioisotope-fueled 1-watt heaters, for initial use on NASA's upcoming Galileo and International Solar-Polar Missions. Each heater must contain passive safety provisions to ensure fuel retention under all credible accident conditions. Initial design reviews raised some concern about the accuracy of the predicted peak reenetry temperature, and about the adequacy of the safety margin under certain unlikely - but not impossible-reentry modes. Of particular concern was the possile release of the accumulated helium inventory from the fuel during the reentry heat pulse, and the potential effect of enhanced heat conduction due to helium buildup in gaps. The latter problem had not been addressed in previous studies. Fairchild carried out a large number of reentry thermal analyses to resolve the analytical uncertainties, and proposed design changes to reduce the thermal coupling between the aeroshell and the fuel capsule. For the computed reentry temperature history of the modified design, the rate of helium buildup in the gaps was analyzed. The analysis accounted for temperature-dependent helium diffusion through the fuel pellet and for leakage to space through the permeable aeroshell. It showed that most of the helium inventory leaves the fuel during reentry, but that it never reaches a continuum pressure in the gaps, and therefore has no significant thermal effect. Under these conditions, the Fairchild-modified design provides ample safety margin against clad failure, even for very unlikely reenty trajectories. The modified design was successfully vibration-tested and was subsequently adopted by the project. Cross Reference CID #8517. There are two copies in the file.

To design, manufacture and analyze custom implants with functional gradation in macrostructure for attachment of amputation prostheses. The external shape of the implant was designed by extracting geometrical data of canine cadavers from computed tomography (CT) scans to suit the bone cavity. Three generations of implant designs were developed and were optimized with the help of fit/fill and mechanical performance of implant-cadaver bone assembly using CT analysis and compression testing, respectively. A final optimized, custom Ti6Al4V alloy amputation implant, with approximately 25% porosity in the proximal region and approximately zero percent porosity in the distal region, was fabricated using Laser Engineered Net Shaping (LENS™)--a laser based additive manufacturing technology. The proposed design changes in the second generation designs, in terms of refining thresholds, increased the average fill of the bone cavity from 58% to 83%. Addition of a flange between the stem and the head in the second generation designs resulted in more than a seven-fold increase in the compressive load carrying capacity of the assembly. Application of LENS™ in the fabrication of present custom fit Ti6Al4V alloy implants enabled incorporation of 20 to 30% porosity in the proximal region and one to two percent residual porosity in the distal portion of the implant. Patient specific prostheses having direct connection to the skeletal structure can potentially aid in problems related to load transfer and proprioception in amputees. Furthermore, application of LENS™ in the fabrication of custom implants can be faster to incorporate site specific porosity and gradients for improving long-term stability.

Purpose – The purpose of this paper is to describe the use of computer simulation for performance improvement analysis for a large‐scale ergonomic intervention and redesign project of a supermarket checkstand. Owing to its relatively complex operating logic, coupled with myriad physical characteristics of grocery items and variable buying patterns, conventional methods of analysis are impractical.Design/methodology/approach – The probability distributions of activity time elements and system characteristics are determined from video analysis of the checkstand operation. A SLAM II model represented the functional logic and random samplings from probability distributions simulated effects of variable grocery characteristics and buying patterns. The utilization indices obtained from the model facilitated prioritizing design improvements. The proposed design changes of the checkstand are implemented in the model by applying scaling factors estimated from the predetermined time standards.Findings – The mean pe...

The accurate description and flow calibration at the exit of a gas turbine combustor is a key point of turbine design. Indeed, the temperature field at the turbine inlet directly impacts both the work extraction by the turbine stages as well as drives the wall heat transfer occurring on the vanes and rotor surfaces. Properly simulating or measuring this critical planar interface has been an extensive topic of research. Despite such efforts, industrial exploitation of the various measures at that interface usually resumes to a quantification of the temperature heterogeneities through the Local Radial Temperature Distortion Factor (LRTDF), thereby loosing major spatial and unsteady information. As lean burn configurations become a standard for aero-engine combustors, the absence of dilution holes reduces the intensity of mixing and the use of more advanced statistical tools should propose an exhaustive representation of the temperature map and mixing quality. Current state-of-the-art numerical design of gas turbine combustor relies on Large Eddy Simulations (LES) giving access to a fully 3-D temporally dependent flow field throughout the combustion chamber. Going beyond LRTDF is therefore possible and advanced analyses of the combustor-turbine interface are accessible to better qualify proposed design changes. In this work, a simple statistical representation of the temperature distribution is introduced and applied for the analysis of a lean burn combustor simulator interface. It is shown that at the exit of this chamber, the temperature samples are distributed following a non-Gaussian shape, highlighting a most probable local temperature largely different from the conventional mean value. The use of high order moments explains such deviations and indicates the presence of strongly segregated zones governed by the technological implementation of effusion cooling systems. Based on this diagnostic, a new and complementary representation of the LRTDF is proposed, accounting for the statistical dimension of the classical (radius, temperature) formulation.

Gas-to-liquid (GTL) products have increasingly become a promising energy resources over the past two decades. Qatar possesses the third largest proven reserve of natural gas in the world, with a net capacity approaching 900 tcf (trillion cubic foot). This has motivated Qatar to develop a long term vision, involving the investment of huge expenditures into world-class commercial plants that convert natural gas into value-added liquid hydrocarbon products. This vision was translated into the Oryx GTL plant in late 2006 and the Shell Pearl GTL plant reported to be the largest in the world, which began operations officially at the end of 2011, leading Qatar to be described as the world capital of GTL. The substantial usage of energy in Fischer-Tropsch (FT) GTL processes and the complexity of energy distribution throughout the process offer opportunities for heat integration and waste heat recovery. The objective of this paper is to carry out an energy integration analysis for a typical GTL process. The approach was started with process simulation to develop the base-case data for the process. Next, energy integration tools were used to optimize energy distribution, heat exchange, and waste heat recovery. Finally, simulation and techno-economic analysis were utilized to assess the performance of the proposed design changes and their economic viability. The resultant pinch diagram showed that a single pinch case was faced with a fixed driving force of 10 oC, in which both external cooling and heating utilities were required to satisfy energy needs. Meanwhile, the Grand Composite Curve (GCC) showed that flue gases cover most of the heating utility while cooling water covers all the required cooling utility. Moreover, the waste heat recovery study supported by HYSYS software illustrated considerable recoveries in steam qualities from discharged flue gases within the FT reactor section. In conclusion, energy integration on a GTL process was realized to be a promising one as the targets for net energy savings were found to be close to 40%. Additionally, generation of various qualities of steam can be obtained in a cost-effective manner. At the top of it, most of the recommended projects have attractive payback periods, below six years.

<div class="section abstract"><div class="htmlview paragraph">Gear whine noise impacts customer perception of vehicle interior quietness in general and sound quality in particular. It has been a frequently occurred annoying phenomenon during vehicle development and much discussed topic regarding transmission NVH refinement in automotive industry. This work pertains to a transmission gear whine issue encountered in prototype evaluations during a vehicle program development process. The effort centers itself on the optimization of transmission gear macroscopic and microscopic parameters to fix the issue which is deemed unacceptable for customers. Specifically, by using multi-body dynamics approach, this work carries out a transmission system whine noise simulation based on optimal gear macro parameter selection and micro tooth flank modification. The obtained results show that the proposed design changes could successfully resolve the issue, which is verified by subsequent test measurement and confirmed by subjective evaluations. The work demonstrates that the containment of gear transmission error is an effective countermeasure to resolve the transmission gear whine noise issue.</div></div>

The purpose of this work is to perform analytical modeling and experimentally produce idealized composite laminates reinforced with high-modulus discontinuous-fiber tows to evaluate the theoretical upper limits of tensile strength as compared to continuous-fiber composites. The idealized composite represents a staggered mosaic of prepreg tape strips of equal width and length. Three-dimensional analysis was performed to evaluate the energy release rate of the possible damage accumulation modes, such as tow delamination and splitting emanating from tape strip ends in plies with different orientations. The effect of residual stress was also evaluated on the delamination propagation energy release rates as well as tow end crack formation loads. Failure mechanisms for unidirectional and quasi-isotropic laminates were established by comparing the calculated energy release rates for tows in different locations to the critical Mode II energy release for axial cracking in the material system. Specially designed experiments were conducted to verify the failure mechanism predictions and evaluate proposed design changes for strength increase in the discontinuous-fiber tow reinforced composites.

This paper describes the work performed to study the shell mode vibration of a large cross-section flue gas duct. The work involved the collection of field vibration data, as well as predictive computational models associated with finite element analysis (FEA) and computational fluid dynamics (CFD). The goal of this work was to use predictive models to ascertain whether a proposed design change would reduce the vibration levels of the duct under similar operating conditions. The vibration observed in the duct was identified as a flow induced vibration (FIV) which excited the shell modes of the duct walls. This case study serves as an example of using predictive computational models (FEA and CFD), calibrated with vibration response data from field measurements, to represent the real world situation as closely as possible within specified budget and schedule constraints. Such calibrated models can be useful for forecasting the effectiveness of various proposed design changes.

During the New Product Development (NPD) cycle, it is important to focus and integrate relevant information into the stages of product conceptualisation, design and development so that they can be used for product and process design effectively. In this paper, a Generic Product and Process Development System (GPDS), which integrates knowledge-based technologies of Rule-Based Expert System (RBES) and Case-Based Reasoning (CBR), is proposed to facilitate product and process development. Although RBES is adopted for sorting product design criteria, relevant past cases are retrieved by the CBR system during product and process design stages. In doing so, previous knowledge in terms of rules and past practices will be made use of during the product and process design stages, resulting in an enhancement of the efficiency of design and operations. By applying GPDS in Hasbro Fast East Limited, the new product design life cycle is greatly shortened with significant reduction in the total development cost.

Purpose This developmental-applied descriptive-exploratory research was conducted to investigate the design of a business model and to evaluate the factors affecting it in a real estate construction and sales company. Design/methodology/approach In the qualitative part of this study, several experts in the Iranian construction and sales industry were identified using the method of purposive judgmental sampling. Then, the primary questionnaire was first sent to three experts for the improvement of the internal validity, where each of the questions, their meanings and validity were examined. Full descriptions of the notions involved in the research were then presented to the experts for confirmability purposes before they were sent the questionnaire for the interview. Tools were then used to analyze the data and develop the model. Findings Information technology, human resources management and organizational infrastructure were chosen as the most influential factors. The marketing and sales factor was identified as the most penetrating factor, and because the business model can influence this factor, it seems logical to choose this factor. Marketing and sales have been identified as the most important factors, and investing in these factors can be effective. According to the result of this research, the most influential factors are information technology factors, human resource management, and organizational infrastructure. A deeper investigation of these factors can be suggested as the subject of future research. Research limitations/implications To continue this research, researchers can implement the factors and check the results between organizations. Also, researchers can examine each of the factors separately and research to advance strategic goals in the field of knowledge management. Practical implications A construction and sales project and even business can be extremely risky if it seems economical and profitable while no business model is formulated for its organization or implementation with notions such as competitive advantage, value chain and portfolio management. A construction company has no way but to constantly strive to achieve competitive advantage in such conditions in order to maintain its position in the business and sustainably generate added value for customers. Social implications By implementing the findings and recommendations of this study, construction and sales companies can not only improve their operational efficiency but also establish a framework within which the whole industry can operate, which will in turn establish the norms for the industry and customers. Originality/value This developmental-applied descriptive-exploratory research was conducted to investigate the design of a business model and evaluate the factors affecting it in a real estate construction and sales company, something that is original and can make a significant contribution to the industry.