This report is the documentation of a master’s thesis which was conducted at Scania CV AB in Södertälje. In this study, the benefits, challenges and conditions of using parametric CAD-models for aiding CFD-simulations and performance-optimization in the product development within internal combustion engines have been assessed. The goal of the thesis included developing and proposing a methodology for design engineers at Scania which will aid them in creating parametric CAD-models which are robust, flexible, comprehensible and intelligent. The study also included assessing the benefits and pre-requisites of such methodology with both practical and theoretical approaches. The ultimate goal of this entire study was to create value for the organization by reducing lead-time in the design process while promoting the production of high quality products. A case-based approach was applied in the study in which modeling strategies resulting from practical investigations and analyzing existing methodologies were implemented on a CAD-model representing the gas-volume of a turbine volute. The chosen strategies were evaluated and subsequently documented as a part of the methodology or discarded depending on its support for the parameterization. The final methodology itself was evaluated based on the quality of the parameterized CAD-model, the time required to create the model and its compatibility to the present design process at Scania CV AB. Finally the methodology was discussed with respect to the different evaluations, and the defined research questions were discussed and answered. The results of the thesis revealed that if parametric CAD-models are made in a structured, standardized and conscious manner, they are able to be highly robust and flexible which gives the models the ability to assume a big set of different forms. The methodology is recommended to be tested in a pilot project and be implemented through internal courses at the company. It was concluded that a methodology which aids the design engineers in creating parametric CAD-models will be the key towards implementing parametric CAD-models in the company and also enabling the many benefits of parameterization, which includes reduced lead-time, enhanced component performance, increased knowledge about the component, and promotion of collaboration among engineers. It was also concluded that parametric models are best suited when the existing design freedom is big and when the time permits performance analyses via optimizations, while challenges include ensuring that the model is parameterized correctly with respect to the CFD-engineers’ wishes while taking into account the requirements from other disciplines. Therefore it is very important to establish a communication between the different engineers. Ultimately, when parametric models are established in the organization, they are recommended to be implemented eventually in both short-term and long-term projects within Scania for its beneficial properties.

With constantly changing regulations on emissions, heavy commercial vehicles manufacturershave to adapt for their products to preserve their quality while meetingthese new requirements. Over the past decades, noise emissions have become a greatconcern and new stricter laws demand companies to decrease their vehicle pass-bynoise target values.To address the requirements from different disciplines, Scania follows a simulationdriven design process to develop new concept models EATS. The collaboration amongengineers from different fields is thereby necessary in order to obtain higher performancesilencers. However, the pre-processing step in terms of acoustic simulationsis time-consuming, which can slow the concept development process.In this thesis, a new method was introduced to automate the pre-processing of silenceracoustic models and allow for design optimisation based on acoustic performanceresults. A common Scania product study case was provided to several theseswithin the NXD organisation. The collaboration among the master thesis workersaimed to demonstrate the benefits of KBE and MDO and how they can be integratedwithin Scania’s current concept development and product introduction processes.The performed work was divided in the following steps: data collection, methoddevelopment and concluding work. The first step consisted in gathering sufficientknowledge by conducting a thorough literature review and interviews. Then, an initialmethod was formulated and tested on a simplified silencer model. Once approvedand verified, the method was applied to the study case EATS.The study case showed that a complex product can have its acoustic pre-processingstep automated by ensuring a good connectivity among the required software anda correct denomination of the geometrical objects involved in the simulations. Themethod investigated how morphological optimisations can be performed at bothglobal and local levels to enhance the transmission loss of a silencer. Besides optimisingthe acoustic performance of the models, the method allowed the identificationof correlations and inter-dependencies among their design variables and ouput parameters.

Background The shipbuilding trends have changed from being single purpose ships only to using modular and flexible parts or systems to carry out multiple missions with as few ships as possible to minimize the ecological and economic impact. A flotilla can become smaller by having multiple ships capable of carrying out various missions instead of single-purpose ships. Objectives The objectives throughout the thesis are to provide an insight into how the trends today are affecting the market of surface ships and to study how a reconfigurable floor can be combined with a sliding bulkhead to be implemented into the cargo space. The developed concept needs to meet the regulations set by DNV-GL, which are an international classification society that is experts in risk management and quality assurance. This master’s thesis focuses on how to implement modularity and flexibility in payload arrangement for surface ships. Method The work process is based on the methodology design thinking’s four phases, which are initiation, inspiration, ideation, and implementation. Throughout the project, a trendwatching was conducted to determine the most impactful trends on the naval market. Using semi-structured interviews, techwatching and brainstorming iterations, a requirements list was defined to support the concept development. The concepts were weighed against each other, and the highest scoring was developed into a parametric CAD model. The model was later compared to the DNV-GL regulations to see whether the developed concept affects existing systems such as HVAC. Results Some of the top trends that have been affecting the naval market lately is modularity, flexibility, and unmanned surface vessels. The developed concept was a combination of a pallet loading floor and cargo floor rollers for reconfigurable floors and garage door-inspired bulkhead. The concept was visualized in Autodesk Inventor Professional 2020 to be further analyzed and display how the concept operates, its functions and how the system compares to DNV-GL regulations. Conclusions The top trends affecting the naval market are modularity, flexibility, and unmanned surface vessels to mention a few. Some of the regulations from DNV-GL that need to be considered when implementing a modular and flexible payload arrangement are fire protection and tightness requirements. However, the regulations can be stricter or changed depending on the role, design, and placement of the payload arrangement.

This master thesis has been executed at Scania CV AB in Södertälje, Sweden. Scania is a manufacturer of heavy transport solutions, an industry which is changing rapidly in order to meet stricter regulations, ensuring a sustainable future. Continuous product improvements and new technologies are required to increase performance and to meet markets requirements. By implementing design optimization in the design process it enables the potential of supporting design exploration, which is beneficial when products with high performance are developed. The purpose was to show the potential of design optimization supported by simulation driven design as a tool in the development process. To examine an alternative way of working for design engineers, elaborating more competitive products in terms of economical and performance aspects. Furthermore, to minimize time and iterations between divisions by developing better initial concept proposals. The alternative working method was developed iteratively in parallel with a case study. The case study was a suction strainer and were used for method improvements and validation, as well as decision basis for the included sub-steps. The working method for implementing design optimization and simulation driven design ended up with a procedure consisted of three main phases, concept generation, detail design and verification. In the concept generation phase topology optimization was used, which turned out to be a beneficial method to find optimized solutions with few inputs. The detail design phase consisted of a parameterized CAD model of the concept which then was shape optimized. The shape optimization enabled design exploration of the concept which generated valuable findings to the product development. Lastly the optimized design was verified with more thorough methods, in this case verification with FE-experts. The working method was tested and verified on the case study component, this resulted in valuable knowledge for future designs for similar components. The optimized component resulted in a performance increase where the weight was decrease by 54% compared with a reference product.

<p>Development of modern aircraft has become more and more expensive and time consuming. In order to minimize the development cost, an improvement of the conceptual design phase is needed. The desired goal of the project is to enhance the functionality of an in house produced framework conducted at the department of machine design, consisting of parametric models representing a large variety of aircraft concepts.</p><p>The first part of the work consists of the construction of geometric aircraft control surfaces such as flaps, aileron, rudder and elevator parametrically in CATIA V5.</p><p>The second part of the work involves designing and simulating an Inverse dynamic model in Dymola software.</p><p>An Excel interface has been developed between CATIA and Dymola. Parameters can be varied in the interface as per user specification; these values are sent to CATIA or Dymola and vice versa. The constructed concept model of control surfaces has been tested for different aircraft shapes and layout. The simulation has been done in Dymola for the control surfaces.</p>

Development of modern aircraft has become more and more expensive and time consuming. In order to minimize the development cost, an improvement of the conceptual design phase is needed. The desired goal of the project is to enhance the functionality of an in house produced framework conducted at the department of machine design, consisting of parametric models representing a large variety of aircraft concepts. The first part of the work consists of the construction of geometric aircraft control surfaces such as flaps, aileron, rudder and elevator parametrically in CATIA V5. The second part of the work involves designing and simulating an Inverse dynamic model in Dymola software. An Excel interface has been developed between CATIA and Dymola. Parameters can be varied in the interface as per user specification; these values are sent to CATIA or Dymola and vice versa. The constructed concept model of control surfaces has been tested for different aircraft shapes and layout. The simulation has been done in Dymola for the control surfaces.

In order to understand the relationship between feeding behavior and the evolution of mammalian skull form, it is essential to evaluate the impact of bite force over large regions of skull. There are about 1,100 bat species worldwide, which represent about 20% of all classified mammal species. Hence, a study in the evolution of bat skull form may provide general understanding of the overall evolution of skull form in mammals. These biomechanical studies are generally performed by first building solid Finite Element (FE) models of skull from micro CT scans. This process of building FE models from micro CT scans is both tedious and time consuming. Therefore a new approach is developed in this research project to build these FE models quickly and efficiently. I have used SolidWorks to build a parameterized, three dimensional surface CAD model of a skull of the short-tailed fruit bat, Carollia perspicillata, by using coordinate data from an STL model of the species. The overall shape of this model closely resembled that of solid model of C. perspiciallata constructed from micro CT scans. Finite element analyses of the solid and surface models yielded comparable results in terms of magnitude and distribution of von Mises stress and mechanical advantage. Using this parametric surface model, the FE plate or shell element models of different bat species were generated by varying two parameters, palate length and palate width. Parametric analyses were performed on these FE plate models of skulls and response surfaces of performance criteria: von Mises stress, strain energy and mechanical advantage were generated by varying the input parameters. After generating response surfaces, species of bats from the morphologically diverse family of New World leaf-nosed bats (Family Phyllostomidae) were overlain on these response surfaces to determine which portions of the performance design space (palate length X width) are and are not occupied. These plots serve as a foundation for understanding the affect of different performance criteria on the evolution of bat skull form.

<p>Throughout the development of this report there will be a brief explanation of what the actual Aircraft Design Process is and in which stages the methodology that the authors are proposing will be implemented as well as the tools that will interact to produce this methodology.</p><p>The proposed tool will be the first part of a methodology that, according to the authors, by integrating separate tools that are currently used in different stages of the aeronautical design, will promote a decrease in the time frame for the initial stages of the design process.</p><p>The first part of the methodology above, that is proposed in this project, starts by creating a computer generated aircraft model and analyzing its basic aerodynamic characteristics “Lift Coefficient” and “Induced Drag Coefficient”, this step will be an alternative to statistical and empirical methods used in the industry, which require vast amount of data.</p><p>This task will be done in several steps, which will transfer the parametric aircraft model to an input file for the aerodynamic analysis program. To transfer the data a “translation” program has been developed that arranges the geometry and prepares the input file for analysis.</p><p>During the course of this report the reader will find references to existing aircrafts, such as the MD-11 or Airbus 310. However, these references are not intended to be an exact computer model of the mentioned airplanes. The authors are using this as reference so the reader can relate what he/she is seeing in this paper to existing aircrafts. By doing such comparison, the author intends to demonstrate that the Parametric Model that has been created possesses the capability to simulate to some extend the shape of existing aircrafts.</p><p>Finally from the results of this project it is concluded that the methodology in question is promising. Linking the two programs is possible and the aerodynamic characteristics of the models tested fall in the appropriate range. None the less the research must continue following the line that has been discussed in this report.</p>

Throughout the development of this report there will be a brief explanation of what the actual Aircraft Design Process is and in which stages the methodology that the authors are proposing will be implemented as well as the tools that will interact to produce this methodology. The proposed tool will be the first part of a methodology that, according to the authors, by integrating separate tools that are currently used in different stages of the aeronautical design, will promote a decrease in the time frame for the initial stages of the design process. The first part of the methodology above, that is proposed in this project, starts by creating a computer generated aircraft model and analyzing its basic aerodynamic characteristics “Lift Coefficient” and “Induced Drag Coefficient”, this step will be an alternative to statistical and empirical methods used in the industry, which require vast amount of data. This task will be done in several steps, which will transfer the parametric aircraft model to an input file for the aerodynamic analysis program. To transfer the data a “translation” program has been developed that arranges the geometry and prepares the input file for analysis. During the course of this report the reader will find references to existing aircrafts, such as the MD-11 or Airbus 310. However, these references are not intended to be an exact computer model of the mentioned airplanes. The authors are using this as reference so the reader can relate what he/she is seeing in this paper to existing aircrafts. By doing such comparison, the author intends to demonstrate that the Parametric Model that has been created possesses the capability to simulate to some extend the shape of existing aircrafts. Finally from the results of this project it is concluded that the methodology in question is promising. Linking the two programs is possible and the aerodynamic characteristics of the models tested fall in the appropriate range. None the less the research must continue following the line that has been discussed in this report.

With constantly changing regulations on emissions, heavy commercial vehicles manufacturers have to adapt for their products to preserve their quality while meeting these new requirements. Over the past decades, noise emissions have become a great concern and new stricter laws demand companies to decrease their vehicle pass-by noise target values. To address the requirements from different disciplines, Scania follows a simulation driven design process to develop new concept models EATS. The collaboration among engineers from different fields is thereby necessary in order to obtain higher performance silencers. However, the preprocessing step in terms of acoustic simulations is time-consuming, which can slow the concept development process. In this thesis, a new method was introduced to automate the pre-processing of silencer acoustic models and allow for design optimisation based on acoustic performance results. A common Scania product study case was provided to several theses within the NXD organisation. The collaboration among the master thesis workers aimed to demonstrate the benefits of KBE and MDO and how they can be integrated within Scania’s current concept development and product introduction processes. The performed work was divided in the following steps: data collection, method development and concluding work. The first step consisted in gathering sufficient knowledge by conducting a thorough literature review and interviews. Then, an initial method was formulated and tested on a simplified silencer model. Once approved and verified, the method was applied to the study case EATS. The study case showed that a complex product can have its acoustic pre-processing step automated by ensuring a good connectivity among the required software and a correct denomination of the geometrical objects involved in the simulations. The method investigated how morphological optimisations can be performed at both global and local levels to enhance the transmission loss of a silencer. Besides optimising the acoustic performance of the models, the method allowed the identification of correlations and inter-dependencies among their design variables and ouput parameters. / Med ständiga förändringar i lagkrav som berör utsläpp måste tillverkare av tunga fordon anpassa sina produkter för att upprätthålla kvalitén samtidigt som de möter de nya kraven. De senaste årtiondena har ljudnivåerna från fordon blivit ett orosmoment, det stiftats striktare lagar som berör den ljudnivå som tunga fordon får emittera under ett förbifartsprov. För att adressera kraven från de olika disciplinerna följer Scania en simuleringsdriven utvecklingsprocess vid utveckling av nya efterbehandlingssystem. Samarbetet mellan ingenjörer från olika fält är därför nödvändigt för att utveckla högre prestanda efterbehandlingsystem. Uppställningen utav de akustiska simuleringarna är tidskrävande, vilket kan leda till en långsam utvecklingsprocess. I detta examensarbete föreslås en ny metod för att introducera en automatiserad uppställning av akustiska simuleringar på efterbehandlingssystem som tillåter optimering av de akustiska egenskaperna. Ett gemensamt studiefall gavs av Scania till flera examensarbeten skrivna vid NXD organisationen. Samarbetet mellan de olika examensarbetena syftade på att demonstrera fördelarna med KBE och MDO och hur de kan bli integrerade i Scanias nuvarande konceptutvecklings- och produktintroduktionsprocess. Examensarbetet är uppdelat i följande steg; datainsamling, metodutveckling och avslutandearbete. Det första steget innefattade insamling av kunskap genom att genomföra en grundlig litteraturstudie och flera intervjuer. Det nästkommande steget innefattade formulering av en initial metod vilken testades på ett simplifierat efterbehandlingssystem. När detta hade verifierats och godkänts applicerades metoden på efterbehandlingssystem i fallstudien. Fallstudien visade att även för en komplex produkt kan uppställningen av de akustiska simuleringarna bli automatiserade genom att säkerställa en bra koppling mellan de olika mjukvarorna och en korrekt benämning av de geometriska objekten involverade i simuleringen. Metoden undersökte hur morfologiska optimeringar kan bli genomförda både på en vittomfattande och lokal nivå för att förbättra transmissionsförlusten i ett efterbehandlingssystem. Förutom att optimera den akustiska prestandan av modellen kunde flera korrelationer mellan de olika konstruktiosparametrar identifieras likväl kunde korrelationer mellan konstruktiosparametrar och systemegenskaperna.