http://localhost:80/xmlui/handle/123456789/1067 Wed, 13 May 2026 18:03:09 GMT 2026-05-13T18:03:09Z http://localhost:80/xmlui/handle/123456789/10938 Title: IQ-RRT*: a path planning algorithm based on informed-RRT* and quick-RRT* Authors: Rahman, Afroze; Kundu, Anindita; Banerjee, Sumanta Abstract: Optimal path planning algorithms such as the RRT* and its variants seek to generate the best feasible path from an initial state to a goal state in the least possible time. Prior work on RRT* has focused on improving the convergence rate of the algorithm while keeping its computational complexity unchanged. Informed-RRT* and quick-RRT* are two such variants that, in certain scenarios, converge to the optimal path faster than RRT* does. This work focuses on the novel addition of informed sampling to quick-RRT* to enhance its convergence rate. The resultant algorithm provides initial solutions with costs comparable to quick-RRT* and convergence rates at par with quick-RRT* in the worst case. The authors have concluded that this new algorithm, named IQ-RRT*, outperforms informed-RRT* and quick-RRT* in a multitude of scenarios. IQ-RRT*, unlike quick-RRT*, is a faster alternative to informed-RRT* even in cluttered environments and mazes with long corridors. Tue, 06 May 2025 00:00:00 GMT http://localhost:80/xmlui/handle/123456789/10938 2025-05-06T00:00:00Z http://localhost:80/xmlui/handle/123456789/10937 Title: Computational analysis of shock wave diffraction for convex slabs Authors: Banerjee, Debiprasad; Halder, Pabitra Abstract: The present study is centered on the vortexlets in the shock wave diffraction over three different slabs (60°, 90°, and 120°) for shock Mach numbers of 1.65, and 3.0. The third-order accurate implicit solver is built on advection upstream splitting along with least squares cell-based method and utilizes the benefits of refined mesh in the regions having high discontinuities. Vortexlet formation, pressure ratio and specific heat flux on the step wall, and movement of the separation point are some of the key aspects of the present analysis. For the numerical simulation of the moving shock, the Finite Volume Method is utilized to find the solutions of the governing equations. Vortexlets, secondary shock, embedded shock, contact surface, slipstream, expansion fan, and vortex are captured precisely. Apart from isopycnics; isobars, isotherms, and velocity contours are plotted as well. Our results emphasize the fact that there exists two types of vortexlets, which are different in their positions apart from their driving mechanisms. Tue, 27 May 2025 00:00:00 GMT http://localhost:80/xmlui/handle/123456789/10937 2025-05-27T00:00:00Z http://localhost:80/xmlui/handle/123456789/10936 Title: Probing the photo induced micro actuation properties of optimized Cu doped Co-34at%-Ni-35at%-Al-31at% ferromagnetic shape memory alloys Authors: Bagchi, Abhishek; Sarkar, Suman; Bysakh, Sandip; Mishra, Vidhyadhar; Das Gupta, K.; Maity, T.; Biswas, Amalendu; Sarkar, Susenjit Abstract: The strange Photo induced micro actuation (PIMA) properties associated with Cu doped Co-Ni-Al Ferromagnetic Shape Memory Alloys (FSMA) has showed enhancement of mechanical properties in our early studies. This enhancement and optimized PIMA properties have opened a scope of various laser-controlled real engineering applications. In this study, we have explored the microstructural scaling and determined the evolved force due to the laser action in optimized Cu doped Co-Ni-Al alloy system with a detailed insight. This unique PIMA property is rare in literature and actual reason are still not explored. EBSD, TEM, AFM/MFM based techniques were further adopted to understand the role of microstructure in more detail. The evolved magnetic domain patterns for actuating and non-actuating alloys have been analyzed in details. Atomic Force Microscopy was adopted to estimate the constitutive mechanical properties of the thin alloy samples by mechanical spectrometry. This estimation was directly used to predict a general trend in force distribution pattern of the Cu-Co-Ni-Al alloys strips through FEM analysis. The crux of FEM based model and its simulated results can be applied for real time PIMA oriented engineering application and device manufacturing. The detail microstructural exploration and its effect in the PIMA response along with generalized deflection-force model have been presented in the current study. Sun, 01 Jan 2023 00:00:00 GMT http://localhost:80/xmlui/handle/123456789/10936 2023-01-01T00:00:00Z http://localhost:80/xmlui/handle/123456789/8681 Title: Computational study of shock diffraction over convex edges Authors: Debiprasad Banerjee and Pabitra Halder Abstract: Abstract Numerical analysis of normal shock diffraction over various step corners is presented using an implicit second-order upwind least squares cell-based method. Slipstream angle calculation for various corner angles and Mach numbers, variation of pressure load and specific heat flux with incident shock Mach numbers and different step corners along the step wall, separation point movement, and reattachment of the streamlines are some of the key features of the present study. Detailed studies have been conducted about the perturbed region enclosed within the diffracted shock wave and the last running expansion wave with the increase in the incident shock Mach numbers. The finite Volume Method is used to solve the governing equations numerically for the simulation of the moving shock. Various flow characteristics such as secondary shock, contact surface, expansion wave, slipstream, vortex, etc are well captured. Apart from isopycnics; Mach contours, isobars, and isotherms are plotted as well. The reattachment region formed after the flow separation near the step edge is mentioned and corresponding lengths over various steps are presented. Separation point movement along the step wall is highlighted and a relevant increase in reattachment length is reported. The slipstream angles get increased with incident shock Mach numbers and with corner angles. However, the rate of increment of slipstream angle decreases gradually. The core of the vortices generated and the reattachment of the separated streamlines are indicated by the two downfalls in the heat flux values. Nomenclature a acoustic velocity cp specific heat at constant pressure h specific enthalpy M Mach number Ms incident shock Mach number p pressure of the gas s specific entropy t time T temperature u x-directional velocity of the gas up induced gas velocity v y-directional velocity of the gas W shock wave velocity Subscripts&Symbols 0 total quantities 1 quantities ahead of the incident shock Description: https://doi.org/10.1088/2631-8695/ad0f02 Tue, 13 Feb 2024 00:00:00 GMT http://localhost:80/xmlui/handle/123456789/8681 2024-02-13T00:00:00Z