Many active flow control strategies have been developed to mitigate flow separation and improve aerodynamic performance. Most studies have focused on optimizing the control action for a given actuator configuration; however, actuator placement is intimately tied to achievable performance. In this paper, we formulate a systematic approach for determining the optimal actuator location for separation control from numerical and experimental fluids data for both stable and unstable systems. High-fidelity numerical fluids simulations have been performed to compute the lift and separation-angle responses to a pulse of localized body-force actuation applied at six distinct locations on the upper surface of the airfoil. These pulse response data are then used to determine the actuator location among the set that can drive the system output to an arbitrary value with the minimum amount of input energy. The results of this study indicate that the optimal actuator locations for controlling lift and separation angle are not identical.

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This article presents an optimized series-parallel hybrid powertrain transformed from a conventional vehicle using an analytical approach without changing the original chassis. The proposed approach is based on a many-objective hybrid powertrain model, which aims to optimize the vehicle weight, fuel consumptions, emissions, and performances. Three different Surrogate Assisted Evolutionary Algorithms (SAEAs) are introduced based on the improved Non-dominated Sorting Genetic Algorithm (NSGA III), Multi-Objective Evolutionary Algorithm Based on Decomposition (MOEA/D) and Multi-Objective Genetic Algorithm (MOGA) for optimization of powertrain components. Initially, the powertrain optimization is performed for Urban Dynamometer Driving Schedule (UDDS) driving cycle with 20% road grade. Thereafter, all the obtained Pareto solutions are combined, screened, and 78 best feasible design points are considered depending on the constraints imposed. Subsequently, 15 design points are randomly selected for validation in Federal Test Procedure (FTP) driving cycle without road grade. It is observed that NSGA III reduces the vehicle weight and fuel consumptions by 4.39% and 46.47% respectively. The powertrain energy efficiency is improved by 57.49%, and the engine is downsized by 40%. The contribution of this article is twofold. First, the many-objective simulation model for hybrid powertrain is developed. Second, SAEAs are implemented as optimization techniques for optimal component sizing and promising results are obtained.

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We present a systematic approach for determining the optimal actuator location for separation control from input-output response data, gathered from numerical simulations or physical experiments. The Eigensystem Realization Algorithm is used to extract state-space descriptions from the response data associated with a candidate set of actuator locations. These system realizations are then used to determine the actuator location among the set that can drive the system output to an arbitrary value with minimal control effort. The solution of the corresponding minimum energy optimal control problem is evaluated by computing the generalized output controllability Gramian.We use the method to analyze high-fidelity numerical simulation data of the

The automatic transmission system is very crucial for the high-speed vehicles, where the planetary or epicyclic gearbox is a standard feature. With the increase in design intricacies of planetary gearbox, mathematical modelling has become complex in nature and therefore there is a need for modelling of multistage planetary gearbox including the shifting scheme. A random search-based synthesis of three degrees of freedom (DOF) high-speed planetary gearbox has been presented in this paper, which derives an efficient gear shifting mechanism through designing the transmission schematic of eight speed gearboxes compounded with four planetary gear sets. Furthermore, with the help of lever analogy, the transmission power flow and relative power efficiency have been determined to analyse the gearbox design. A simulation-based testing and validation have been performed which show the proposed model is efficient and produces satisfactory shift quality through better torque characteristics while shifting the gears. A new heuristic method to determine suitable compounding arrangement, based on mechanism enumeration, for designing a gearbox layout is proposed here. An important finding on automotive gear shift quality due to closer gear ratio is also reported in this work.

This article proposes a fuzzy based fuel-efficient propulsion selection logic for a hybrid electric vehicle (HEV) in ‘Highway Fuel Economy Test (HWFET)’ driving cycle. Optimal utilisation of combustion engine, in HEV, reduces the fossil fuel consumption. This can be realized through an electronic control unit, embedded with effective propulsion selection logic that governs the power split device in series-parallel HEV. A propulsion control logic, based on the road gradeability, velocity, torque demand and vehicle battery state of charge (SOC) is presented in this article. A comparison with conventional propulsion selection logic based system shows that the HEV modelled with proposed fuzzy based one, results in better speed tracking with steep road grades, as it provides better torque supply at desired speed points. The analysis indicates a reduction in consumption of both the fossil fuel as well as the electrical fuel (SOC).

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