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ECS system simulation - Architecture and performance optimization from the early phases of the system design The trend today in aircraft thermal design leans towards electronic system integration requiring higher heat densities and a more frequent use of composite primary structures. All these factors require thermal management and architecture design to achieve a suitable robustness, even in the early design stages. The thermal architecture should be able to prevent the risks of damage to temperature-sensitive equipment and limit the expensive overdesign of aircraft systems. ## Challenge The optimization of the thermal architecture is considered one of the key factors of future aircraft development. It requires a composite pyramid of simulation tasks to be set and managed: from equipment to aircraft section simulation to the global aircraft thermal analysis. Adopting this approach gives rise to a number of difficulties due to the variety of physical models to be integrated and the partners, techniques and tools interacting at each level of the pyramid. This case study from Leonardo’s Environmental Control System (ECS) department shows how the different design disciplines involved are handled effectively through process integration and automation, enabling the optimization of the overall performance from the early stages of system design. One of the systems considered in the ECS design at Leonardo is the air conditioning pack and distribution system. The air, supplied from the engine compressor, is processed in the conditioning pack before being distributed to the fuselage compartments. Enhancing the efficiency of the thermal architecture implies several constraints and requirements relating to standards-compliance and safety regulations. Designers must adhere to given A/C configurations and maintain suitable thermoacoustic insulation and temperature levels for both the cabin and cockpit. ## Solution First, engineers at Leonardo used the TPM approach to compare the performance of two alternative architectures, preferring a parallel layout composed of an underfloor and a low pressure air line fed from the mixing chamber and distributing the airflow in parallel through a set of risers. Next, after building the model for the selected architecture and its subsystems in LMS.Amesim, the workflow for the air nozzle shape optimization was built in modeFRONTIER. “The optimization platform helped us reduce pressure loss and noise level to the minimum” says Gaetano Mirra (CTO, General Systems - ECS and Ice protection specialist at Leonardo). ## Benefits “modeFRONTIER automation and integration capabilities enabled us to simultaneously consider the fluid dynamic and acoustic analysis and easily handle the data flow including Catia, StarCCM+ ans PostPRO simulations in a unique environment” continued Mirra. “We found the best configurations possible for the nozzle shape and refined the thermal architecture design, further enhancing passenger comfort in terms of cabin thermal environment”.

Using modeFRONTIER to integrate GT-Valve train and GT-Power models for valve event optimization Cummins Engine, a leader in the manufacturing of diesel and natural gas-powered engines for a wide range of transportation and equipment purposes, has created a new power module ready to take on the stringent US - EPA regulations. It is significantly more compact and cost-effective than medium-speed engines at the same horsepower. It took 150 engineers to design it, and modeFRONTIER helped the High Horsepower group find the optimal valve timing, hence reducing fuel consumption. ## Challenge When designing piston engines, timing when opening and closing inlet and exhaust valves is a crucial parameter impacting the fuel consumption / power output ratio. Typically, delaying the Exhaust Valve Closing (EVC) and anticipating the Intake Valve Opening reduces Exhaust Gas Residuals, resulting in lower fuel consumption. Among the complex models composing the 16-cylinder engine, Cummins designers used GT-Suite (Valve Train and Power modules) to simulate valve event performance and dynamics. For optimal engine performance, valve timing and lift profile need to be perfected for given breathing configurations defined by engine speed, and valve and port geometry and performance. ## Solution Finding the optimal valve timing configuration required a two-step process; to start, a first workflow was created in mode FRONTIER and used to automate the calibration process. Valve train parameters were automatically adjusted with modeFRONTIER to calibrate the GT model and match measured push tube load. The second phase consisted in a second workflow, which was used to investigate the design space; initially with response surfaces and subsequently with the direct optimization algorithms NSGA and Hybrid - to find the best values for 12 output parameters measuring the exhaust and intake cam timing angles, the volumetric efficiency and the Brake Specific Fuel Consumption (BSFC)1. ## Benefits During both project phases, modeFRONTIER proved highly reliable for reducing design cycle time and improving the performance of the valve train system. From the outset “it helped drastically reduce the time taken for calibrating GT models” said Ambikapathy Naganathan (Structural and Dynamics Analysis Engineer at Cummins). “modeFRONTIER has an excellent capability for integrating with multiple GT models and post processing tools.” Continued Eng. Naganathan: “in fact it helped us link those GT models more efficiently and complement the in-house optimization tool, while at the same time maintaining concurrent use by different analysts in different locations.”

Optimization time dropped from 20 to 4 days, with a 44% safety improvement SACMI is a global OEM (Original - Equipment - Manufacturer), market leader in the production of machines and complete plants for the Ceramics, Packaging (Beverage and Closures&Containers), Food and Plastics industries. ## Challenge Among other machines, the SACMI packaging division manufactures the Compression Molding Machine (CCM) able to transform plastic resin pellets into semi-finished caps. During the injection phase, a pneumatic piston allows for the melted pellet to be injected inside the mold. The piston is subject to a high acceleration rate and continuous collisions which call for a compromise between stress and weight, in order to limit the risk of failure. ## Solution The goal of the analysis was to find a light but strong piston geometry in order to improve the Compression Molding Machine performance in terms of tensile and yield strength. The first optimization study was carried out manually for a 12mm piston, while the second study on a 16mm piston took advantage of modeFRONTIER optimization platform by capturing the piston model, previously created in Solidworks and analyzed in Ansys Workbench, and improving the geometry and performance. Piston geometry modifications led to a 33% safety index increase in the case of manual analysis and 44% in the case of the model optimized with modeFRONTIER. ## Benefits modeFRONTIER enabled the CAE expert to exploit his original inspiration - which led to an improved piston geometry - by evaluating a higher number of configurations (+240%) in less time and by further enhancing the safety performances. The time for the optimization process dropped from 20 to 4 days, 3 of which were required for manual setup and 1 for automated evaluation. “I wasn’t an experienced modeFRONTIER user - says Andrea Minardi, CAE specialist at SACMI Packaging Division- so I found the Optimization Wizard very useful: it supported the choice of the number of designs, of the algorithm and of the number of iterations according to the time available for the whole analysis.” The automation of the design optimization process allowed to consider a wider range of possibilities and to analyse in depth the influence between the design parameters and the objectives.

modeFRONTIER helps Whirlpool Corporation create more consistent models by increasing fidelity and performance Whirlpool Corporation is the world leader in the appliances industry, with 67 manufacturing and technology centers operating globally and strongly committed to maintaining its innovation-oriented strategy. Whirlpool has successfully devised a system of tools that enables the ongoing connection and engagement throughout the network of design teams worldwide. modeFRONTIER plays a key role in streamlining system modeling tasks and helps Whirlpool rationalize the whole process and adapt it efficiently to regional peculiarities, providing diversified product lines. ## Challenge Sophisticated appliance design is underpinned by complex mechanical and electrical requirements and demands advanced engineering knowledge in dynamics, structures, fluids, thermodynamics and controls. This calls for an in-depth understanding of both market expectations and engineering dynamics at system level. Most of all, the ability to evaluate product performance before identifying specific requirements accelerates the subsequent adaptation to regional peculiarities. Connecting all players doing similar tasks is crucial for identifying not just a single solution, but a set of solutions so as to map out the relevant space before laying down the requirements. Balancing individual and team workloads based on such flexible approach is challenging task which can be tackled only with appropriate mindset and tools. ## Solution System modeling as concieved by engineers at Whirlpool combines “Attribute” and “Architecture” performance together and relies upon modeFRONTIER as the multidisciplinary project dashboard: it “provides us with an easy way to combine attribute models – defining subsystems configurations - and evaluate product performance without specific requirements”, says Greg Garstecki (Principal Engineer, Fabric Care Advanced Development at Whirlpool). This results in a “correlation and calibration document” described by John Mannisto (Engineering Director, Simulation Based Design at Whirlpool) as “a tool for measuring our confidence in a particular simulation, and for understanding the variations in our processes.” While the interrelated effects of the involved electro-mechanical simulation variables are identified at an early stage, modeFRONTIER multi-objective optimization capabilities allows us to reach a high level of performance once the product requirements are then set”, points out Garstecki. ## Benefits Modeling product performance at system level is an evolutionary process, from the mere description of specific performance metrics by means of empirical test data to the physics-based predictive model. modeFRONTIER helps Whirlpool create more consistent models by increasing fidelity and performance: this in turn allows for a larger inference space for design and continuous connection at a system level to lay down the basis for knowledge capture. “System modelling is where modeFRONTIER really shines”, Mannisto added. “It’s like a symphony conductor, pulling together the individual subsystem outputs to understand the interplay between them. This lets us explore and discover possibilities we’ve never even considered.”

modeFRONTIER helped the team meet multiple structural constraint and significantly reduce the rocket weight. Since the early 2000s, the Hybrid Propulsion Team at the University of Brasilia has been a pioneer in the development and test of hybrid rocket engines and small sounding rockets. By following a system design approach based on the multidisciplinary optimization technique, the Team has developed a conceptual hybrid rocket motor, attaining a valuable technological option for the reentry maneuvering system of SARA, the reusable satellite designed by the Brazilian Institute of Aeronautics and Space. ## Challenge Solid and liquid rocket propulsion systems are traditionally considered the most convenient technological solution for deboost motor systems. Owing to the improvements in solid fuel regression rates, hybrid propellant rocket engines represent a valid alternative. The team analyzed three different propulsion settings, combining the paraffin as solid fuel with cold gas fuel, thereby responding to the SARA reentry procedure requirements. The final design should meet both the geometric constraints, linked to total mass limitation and the performance indicators for the mission: deboost impulse should produce a deceleration ranging from 235 to 250 m/s and the motor burning. ## Solution The Team took in account the key parameters impacting the performance of the hybrid engine: grain configuration, combustion efficiency, oxidizer tank pressure and nozzle configuration together with geometrical configuration. The two-step sensitivity analysis performed with modeFRONTIER - dedicated tools led to the selection of the variables showing significant dependencies with design constraints and objectives. These key elements were brought together to build a workflow capable of both preserving the simplicity of hybrid propulsion systems. This automatic framework drove the search for the geometric configuration, yielding to the higher mass reduction for each of the three configurations. “The routine piloted by the modeFRONTIER® workflow helped generate, evaluate and select design alternatives along the optimization process, resulting in lighter engines than the liquid and solid motors previously studied.” said Manuel Nascimento Dias Barcelos, head of the Hybrid Propulsion Team. ## Benefits modeFRONTIER streamlined the design effort conducted for the hybrid propellant engines based on liquefying fuel (solid paraffin) and two different gas fuels: H2O2 and self-pressurizing N2O. The estimated mass of the reentry system for the cases addressed in the study varied from 22 to 29 kg, lower than either liquid bipropellant or solid engines formerly proposed. “The optimization process discussed in this work can be considered an essential tool for the preliminary phase design of hybrid rocket propulsive systems”, concluded Manuel Nascimento Dias Barcelos.

Optimal Design of an Unmanned High-Altitude Solar-Powered Airplane In recent years the development of High Altitude/ Long Endurance (HALE) solar-powered unmanned aerial vehicles (UAVs) has been gaining importance. Such aircrafts could serve as “pseudo satellites”, with the advantages of being closer to the ground, more flexible and less expensive when compared to common satellites. Using a combination of a solar array and batteries and without requiring sophisticated assisted take-off systems these UAVs could potentially cover a 1,000 km diameter area and process about 425,000 cell phone conversations while sustaining long endurance flights. ## Challenge Stability and control are critical issues in any aircraft design, more so in this case particular care was paid to this problem especially considering that the airplane flies at altitudes of up to 17km. Another concern is how to identify the best setup of battery packs and power system in order to comply with aircraft standards and regulations. The researchers of the Brazilian Instituto Tecnológico de Aeronáutica worked on the enhancement of a light-weight solar-powered UAV model, featuring a rectangular wing with a conventional tail connected to the wing by means of a boom and two engines located on the inner wing. The baseline airplane gross weight was 30.1 kg and the battery fraction, impacting the overall weight, was very high. With this in mind, the researchers sought the best configuration of selected parameters - geometry, aerodynamics, structures, stability, weight and systems. The multi-objective optimization was concerned with maximizing the available electrical power while reducing the gross weight of the airplane configuration. ## Solution The multi-disciplinary workflow built with modeFRONTIER took into account the stability constraints and the area of solar panels, which could not exceed the dedicated portion of the wing. The objective of the optimization was to minimize weight and maximize the power surplus. The wing area range could vary between 30 and 60 m2, and after 40 generations with 30 individuals each, the MOGA-II algorithm returned a group of feasible designs. The best configuration featured a 50% expansion in wing area, admitting a larger solar panel resulting in a considerably higher power availability with a slight increase in aircraft weight. ## Benefits The choice of modeFRONTIER as the optimization tool provided researchers with a large variety of configurations in less than one day’s computation. For each design solution, engineers identified the strengths, weaknesses and typical values of the variables in order to introduce the improvements sought. “The disciplines of aerodynamics, structures, stability, weight, and systems were all considered and integrated in a modeFRONTIER workflow, capable of providing a relatively simple resizing, but highly realistic airplane”, said Bento Silva de Mattos of the Instituto Tecnológico de Aeronáutica. This case study clearly demonstrates the added value achieved by combining optimization and simulation. With only a few semi-empirical mathematical models and data obtained with the computations and the application of simple theories, it was possible to reach the optimal design and verify the consistency of the solution.

Optimized heating plate dramatically improved long-term DSSC performance TRE (Tozzi Renewable Energy), a producer of renewable energy, was looking to improve the long-term stability of its photovoltaic Dye-Sensitized Solar Cells (DSSC) - widely considered the next generation solar cells - under development by TRE start-up company Daunia Solar Cell. Compared to the current generation, DSSCs are cheaper to produce, work well in low-light conditions and are suitable for most engineering applications. They are particularly well suited to architectural applications where aesthetics are important, offering design choices that were previously unavailable (i.e. color and transparency). However, the issue of unconfirmed long-term DSSC stability was standing in the way of satisfying stringent manufacturing certification standards. ## Challenge In terms of commercialization, stable performance over time is crucial. With long-term stability dependent on the quality of the sealing process and the quality of the sealing process dependant on uniform heat distribution over the heating plate surface, one of the main objectives was to improve thermal uniformity. Using modeFRONTIER optimization software, TRE was able to change the heating plate design and achieved optimal thermal distribution, guaranteeing an effective sealing process. ## Solution The solution involved a two step process. In the first step, ANSYS Workbench was used to create a CAD (Computer Aided Design) model representing the initial heating plate configuration based on experimental data. This data was the basis for an FE (Finite Elements) model, required for performing transient thermal analysis. This served to find the materials that would perform best in the optimization run and reach the optimization objective. This procedure was necessary to establish the right setup and validate the computation procedure based on the real reference model. The second step involved deploying the modeFRONTIER optimization platform to modify geometric parameters, increase the thickness of the insulating refractory and the dimensions of the heating coils. modeFRONTIER simulations generated over 250 candidate designs before pinpointing the best design and the optimal time required for the heating process to achieve proper sealing ## Benefits modeFRONTIER thoroughly explored the design space before converging to the optimal heating plate configuration which now distributes heat evenly across the entire surface, directly impacting sealing process quality and ultimately improving long-term DSSC stability. Furthermore, by automating the entire design optimization process with modeFRONTIER, TRE successfully managed to improve the quality of the heating plate, saving both time and money. As Alessio Antonini, Technology Manager of Daunia Solar Cell says, “Thanks to modeFRONTIER, the operator no longer needs to take a trial and error approach to simulations, but rather can use the “artificial intelligence” of the optimization method to automatically seek and find the best combination of input parameters”.

The optimization platform helped the BMW team create a reliable transient cooling system model When it comes to reducing fuel consumption, one effective strategy is to improve the performance of an engine’s transient cooling system. The Diesel Engine Development Department at BMW used modeFRONTIER to optimize engine parameters related to the cooling system and to support the validation steps for the newly updated thermal model, in this way determining an accurate framework for comparing and optimizing different cooling packages. Challenge In order to identify better configurations for the transient cooling system of the six cylinder/225kW diesel engine, the team of BMW engineers developed the air side and coolant circuit model using Kuli, supported also by 3D-CFD simulations. To validate the model, measurements were taken of two different driving cycles and load step on the test bench. After comparing the coolant heat balance for oil and water circuits in the vehicle and on the test bench, results showed significant differences, even for very similar engine operating points. In particular, the wind speed impacting the crankcase, the oil pan and the cylinder head beside the actual thermal conditions under the vehicle hood are difficult to precisely determine on the test bench, affecting the reliability of related transient cooling simulations. To increase confidence in the reliability of such simulations, the engine model was refined to reduce measurement divergence observed during validation tests. ## Solution The coolant circuit and the air path models represented in the engine model included two main groups of key parameters requiring enhancement: five heat transfer coefficients and four heat capacities. modeFRONTIER allowed the engineers to set up an effective optimization workflow that was capable of automatically interacting with the Kuli engine model and detecting the optimal configuration for the nine parameters. Günther Pessl, Head of Simulation at BMW says that “the easy-to-build integration between the two software enabled faster identification of the best heat transfer coefficients and thermal inertia in the engine analyzed.” When transferring the test bench model to the real vehicle model, some parameters indicated fluctuations during the validation cycles, especially oil temperatures which showed the biggest deviation during the hill climb. “Thanks to the optimization loop performed on the hill climb cycle, the engine parameters were refined, resulting in a significant improvement in accuracy measured on the Miramas BMW test track” says Günther Pessl. ## Benefits modeFRONTIER helped the BMW team create a reliable transient cooling system model, compliant with new testing guidelines and accurate enough to be reused for comparing and optimizing different cooling packages. The software contributed to a significant reduction in oil temperature and coolant side model errors and improved related temperature trends. Additionally, the automation capabilities of modeFRONTIER together with its powerful optimization algorithms, enabled automatic fine tuning of the parameters that supported and shortened the model validation steps.

Bottero innovates with optimized high performance mold-motion Leading in the glass industry is Bottero’s declared ambition. The recent launch of E-MOC, a family of mold opening and closing mechanisms (MOC), has challenged the hollow glass industry. E-MOC introduces a completely new cooling concept, granting the possibility to achieve the proper temperature profile, according to the type of process required for the application field. Challenge “The innovative idea behind E-MOC design is the result of our R&D team’s work: numerous constraints were limiting the possibility of changing the machinery design, so modeFRONTIER, the multi-objective optimization platform, came to our help”, says Marcello Ostorero, Structural and Fluid Dynamics Simulation Department Manager at Bottero. The mechanism had to be equipped with a universal mold holder providing efficient cooling and, when mounted, it had to be readily accessible and installable on both new and existing machines. The optimal system performance called for a smooth and precise mold motion, with fast closing time, and maximum closing and clamping forces. ## Solution The complexity of the problem was tackled with modeFRONTIER within two optimization cycles. The aim of the first one was to minimize mold motion oscillations. The results were then used to conduct a sensitivity analysis, which revealed the piston center movement as the most important variable for mechanism stability, but the geometrical constraints did not allow the piston to maintain the optimal trajectory. This unexpected obstacle was bypassed by replacing the single large piston with three smaller ones. In the second optimization cycle modeFRONTIER guided the model adjustments to minimize mechanism lability and oscillations, while keeping constant the newfound optimal values of component geometries and of piston center movement. ## Benefits “Due to the intricate nature of the required mechanism, the systematic optimization approach proposed by modeFRONTIER was the only way to obtain a functioning high-performance design”, says Ostorero, “modeFRONTIER managed to find a fine balance between a high number of rigorous constraints and adjust the model geometry to the most important mechanism specifications so as to increase its efficiency and quality, while successfully driving a number of software, each solving a single aspect of the problem, integrated in a single workflow”.

Multidisciplinary collaboration made easy at Airworks Engineering Airworks, a multidisciplinary company for mechanical engineering, was facing the challenge of improving efficiency in the conversion of wind energy into electrical power by optimizing the whole assembly of a wind power unit rotor. ## Challenge Experts in wind power unit, specialists in CAD (Computer Aided Design) and CFD (Computational Fluid-Dynamics) professionals from different organizations were involved in a complex design scenario and needed to collaborate by effectively sharing a different kinds of information and resources. Engineers from the University of Trieste prepared the parametric CAD model and set up CFD simulations, while Airworks took care of aerodynamic performance calculations of the wind rotor blade, and subsequently performed optimization analysis with modeFRONTIER, the multidisciplinary optimization platform. The need for a common platform to share results emerged rapidly, and was successfully tackled with SOMO software solution (now evolved in VOLTA SPDM enterprise platform). This enabled the seamless execution of inter-organizational simulation workflows. ## Solution With SOMO each partner of the simulation workflow was able to contribute to the project providing its own high level of collaboration. The CAD expert generated the geometry of the blades providing a parametric model and the CAD solution used to update it, while the CFD expert set up the aerodynamic simulation model, which used the geometry to evaluate the rotor aerodynamic performance. Both simulation workflows were made available to partners in a shared repository. Then the wind power unit expert was able to integrate his performance evaluation software into an automated multi-disciplinary workflow. Ultimately he used the workflow to evaluate the power efficiency of the system and to optimize it in a complete range of environmental conditions. ## Benefits Through the entire process, simulation data and engineering knowledge were effectively managed and shared through SOMO, allowing a faster process and a considerable resource-saving”, says Stefano Picinich, Airworks Engineering Managing Director. With the set up of the optimization workflow, Airworks professionals were able to explore and evaluate new parametric geometry, leading to innovative designs, analyzed by the decision-maker via the post-processing tools. The considerable result was of a wind turbine design with an outstanding power coefficient and an annual energy production increase of respectively 1.26% and 0.47%.