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Rameez Badhurshah

Bio: Rameez Badhurshah is an academic researcher from Indian Institute of Technology Bombay. The author has contributed to research in topics: Turbine & Oscillating Water Column. The author has an hindex of 6, co-authored 12 publications receiving 121 citations. Previous affiliations of Rameez Badhurshah include Indian Institute of Technology Madras.

Papers
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TL;DR: In this article, a bidirectional impulse turbine was simulated using CFD technique and optimized using multiple surrogates approach to enhance the robustness of the optimization process by using different surrogates such as response surface approximation, radial basis function, Kriging and weighted average surrogate.

64 citations

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TL;DR: In this paper, a bidirectional flow impulse-turbine used in a wave energy harvesting system has efficiency less than 40%, and it is required to design the turbine for a higher efficiency.

43 citations

Journal ArticleDOI
TL;DR: In this article, the authors study the effect of the non-linearity of the bistable spring on the size of the lock-in regime of a cylinder placed in uniform flow.

14 citations

Journal ArticleDOI
TL;DR: The Kriging variants such as ordinary, universal, and blind along with commonly used response surface approximation (RSA) model were used in the present problem, to optimize the performance of an air impulse turbine used for ocean wave energy harvesting by CFD analysis.
Abstract: Surrogates are cheaper to evaluate and assist in designing systems with lesser time. On the other hand, the surrogates are problem dependent and they need evaluation for each problem to find a suitable surrogate. The Kriging variants such as ordinary, universal, and blind along with commonly used response surface approximation (RSA) model were used in the present problem, to optimize the performance of an air impulse turbine used for ocean wave energy harvesting by CFD analysis. A three-level full factorial design was employed to find sample points in the design space for two design variables. A Reynolds-averaged Navier Stokes solver was used to evaluate the objective function responses, and these responses along with the design variables were used to construct the Kriging variants and RSA functions. A hybrid genetic algorithm was used to find the optimal point in the design space. It was found that the best optimal design was produced by the universal Kriging while the blind Kriging produced the worst. The present approach is suggested for renewable energy application.

12 citations

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TL;DR: In this article, the authors present results from two-dimensional numerical simulations based on Immersed Boundary Method (IBM) of a cylinder in uniform fluid flow attached to bistable springs undergoing Vortex-Induced Vibrations.

10 citations


Cited by
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Journal ArticleDOI
TL;DR: The extent to which the use of metamodeling techniques inmultidisciplinary design optimization have evolved in the 25 years since the seminal paper on design and analysis of computer experiments is addressed.
Abstract: The use of metamodeling techniques in the design and analysis of computer experiments has progressed remarkably in the past 25 years, but how far has the field really come? This is the question addressed in this paper, namely, the extent to which the use of metamodeling techniques in multidisciplinary design optimization have evolved in the 25 years since the seminal paper on design and analysis of computer experiments by Sacks et al. (“Design and Analysis of Computer Experiments,” Statistical Science, Vol. 4, No. 4, 1989, pp. 409–435). Rather than a technical review of the entire body of metamodeling literature, the focus is on the evolution and motivation for advancements in metamodeling with some discussion on the research itself; not surprisingly, much of the current research motivation is the same as it was in the past. Based on current research thrusts in the field, multifidelity approximations and ensembles (i.e., sets) of metamodels, as well as the availability of metamodels within commercial soft...

330 citations

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TL;DR: A qualitative evaluation and a mental model is proposed which is based on quantitative results and findings of authors in the published literature to provide practical guide for researchers and practitioners in industry to choose the most appropriate surrogate model based on incomplete information about an engineering design problem.
Abstract: In simulation-based realization of complex systems, we are forced to address the issue of computational complexity. One critical issue that must be addressed is the approximation of reality using surrogate models to replace expensive simulation models of engineering problems. In this paper, we critically review over 200 papers. We find that a framework for selecting appropriate surrogate modeling methods for a given function with specific requirements has been lacking. Having such a framework for surrogate model users, specifically practitioners in industry, is very important because there is very limited information about the performance of different models before applying them on the problem. Our contribution in this paper is to address this gap by creating practical guidance based on a trade-off among three main drivers, namely, size (how much information is necessary to compute the surrogate model), accuracy (how accurate the surrogate model must be) and computational time (how much time is required for the surrogate modeling process). Using the proposed guidance a huge amount of time is saved by avoiding time-consuming comparisons before selecting the appropriate surrogate model. To make this contribution, we review the state-of-the-art surrogate modeling literature to answer the following three questions: (1) What are the main classes of the design of experiment (DOE) methods, surrogate modeling methods and model-fitting methods based on the requirements of size, computational time, and accuracy? (2) Which surrogate modeling method is suitable based on the critical characteristics of the requirements of size, computational time and accuracy? (3) Which DOE is suitable based on the critical characteristics of the requirements of size, computational time and accuracy? Based on these three characteristics, we find six different qualitative categories for the surrogate models through a critical evaluation of the literature. These categories provide a framework for selecting an efficient surrogate modeling process to assist those who wish to select more appropriate surrogate modeling techniques for a given function. It is also summarized in Table 4 and Figs. 2, 3. MARS, response surface models, and kriging are more appropriate for large problems, acquiring less computation time and high accuracy, respectively. Also, Latin Hypercube, fractional factorial designs and D-Optimal designs are appropriate experimental designs. Our contribution is to propose a qualitative evaluation and a mental model which is based on quantitative results and findings of authors in the published literature. The value of such a framework is in providing practical guide for researchers and practitioners in industry to choose the most appropriate surrogate model based on incomplete information about an engineering design problem. Another contribution is to use three drivers, namely, computational time, accuracy, and problem size instead of using a single measure that authors generally use in the published literature.

137 citations

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TL;DR: In this paper, the authors provide a review and discuss the development of the OWC concept of wave energy converters in general and the evolved variation of the M-OWC more specifically.
Abstract: Wave energy development continues to advance in order to capture the immense ocean energy available globally. A large number of wave energy conversion concepts have been developed and researched to date but we are still not able to see a convergence of technologies. This provides the requirement and additional opportunity for further research. This paper provides a review and discusses the development of the OWC concept of wave energy converters in general and the evolved variation of the M-OWC more specifically. The review outlines the increased potential of the M-OWC concept and its current state through its advancement in recent years. Although still under development the M-OWCs have the potential to provide promising results, through the various innovative concepts under consideration, and support the progression and further development of wave energy as another serious contender in the renewables energy mix.

66 citations

Journal ArticleDOI
TL;DR: In this article, a numerical work relying on design optimization is reported to show the dependency of power extraction capability to the operating range of the turbine, and a surrogate approximation model was constructed to find an optimal design.

57 citations

Journal ArticleDOI
TL;DR: A review of the four main methods to convert the (thermo)acoustic power into electricity is provided in this article, focusing on possible configurations, operating characteristics, output performance, and analytical and numerical methods to study the devices.
Abstract: Thermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently into electric power. This article provides a review of the four main methods to convert the (thermo)acoustic power into electricity. First, loudspeakers and linear alternators are discussed in a section on electromagnetic devices. This is followed by sections on piezoelectric transducers, magnetohydrodynamic generators, and bidirectional turbines. Each segment provides a literature review of the given technology for the field of thermoacoustics, focusing on possible configurations, operating characteristics, output performance, and analytical and numerical methods to study the devices. This information is used as an input to discuss the performance and feasibility of each method, and to identify challenges that should be overcome for a more successful implementation in thermoacoustic engines. The work is concluded by a comparison of the four technologies, concentrating on the possible areas of application, the conversion efficiency, maximum electrical power output and more generally the suggested focus for future work in the field.

53 citations