What is Multiphysics? Definition and Examples

Academic presentation at the International Conference on the Cooperation and Integration of Industry, Education, Research and Application, arranged by Henan University of Science and Technology, Luoyang, 21. - 23.11.23

Selection of a high performance alloy for gas turbine blade using multiphysics analysis

With the extensive increase in the utilization of energy resources in the modern era, the need of energy extraction from various resources has pronounced in recent years. Thus comprehensive efforts have been made around the globe in the technological development of turbo machines where means of energy extraction is energized fluids. This development led the aviation industry to power boost due to better performing engines. Meanwhile, the structural conformability requirements relative to the functional requirements have also increased with the advent of newer, better performing materials. Thus there is a need to study the material behavior and its usage with the idea of selecting the best possible material for its application. In this work a gas turbine blade of a small turbofan engine, where geometry and aerodynamic data was available, was analyzed for its structural behavior in the proposed mission envelope, where the engine turbine is subjected to high thermal, inertial and aerodynamic loads. Multiphysics Finite Element (FE) linear stress analysis was carried out on the turbine blade. The results revealed the upper limit of Ultimate Tensile Strength (UTS) for the blade. Based on the limiting factor, high performance alloys were selected from the literature. The two most recommended alloy categories for gas turbine blades are NIMONIC and INCONEL from where total of 21 types of INCONEL alloys and 12 of NIMONIC alloys, available on commercial bases, were analyzed individually to meet the structural requirements. After applying selection criteria, four alloys were finalized from NIMONIC and INCONEL alloys for further analysis. On the basis of stress-strain behavior of finalized alloys, the Multiphysics FE nonlinear stress analysis was then carried out for the selection of the individual alloy by imposing a restriction of Ultimate Factor of Safety (UFOS) of 1.33 and yield strength. Final selection is made keeping in view other factors like manufacturability and workability in due consideration

A review of infrared thermography applications for ice detection and mitigation

Ice accretion on various onshore and offshore infrastructures imparts hazardous effects sometimes beyond repair, which may be life-threatening. Therefore, it has become necessary to look for ways to detect and mitigate ice. Some ice mitigation techniques have been tested or in use in aviation and railway sectors, however, their applicability to other sectors/systems is still in the research phase. To make such systems autonomous, ice protection systems need to be accompanied by reliable ice detection systems, which include electronic, mechatronics, mechanical, and optical techniques. Comparing the benefits and limitations of all available methodologies, Infrared Thermography (IRT) appears to be one of the useful, non-destructive, and emerging techniques as it offers wide area monitoring instead of just point-based ice monitoring. This paper reviews the applications of IRT in the field of icing on various subject areas to provide valuable insights into the existing development of an intelligent and autonomous ice mitigation system for general applications

Optimization of ground icing protection for aircraft: Snow endurance tests, rheological analysis and thermography of anti-icing fluids

Poster presentation at the colloquium seminar, arranged by Université du Québec à Chicoutimi (UQAC), Chicoutimi, 11.10.2023

Fluid solid interaction simulation of CFRP shell structure

Accepted manuscript version. Published version available at http://nonlinearstudies.com/index.php/mesa/article/view/1532.This work attempts to model the dynamic behavior of Carbon Fiber Reinforced Polymer (CFRP) shell structure subjected to water shock wave to improve the results presented in the study by Khawaja et al., 2014. In the previous study, the real physical problem was simplified by decoupling the fluid and the structural phenomena, applying the recorded experimental fluid pressure load to the CFRP shell structure. The current study involves not only structure modeling, as given in the earlier study, but also fluid behavior using the Arbitrary Lagrangian-Eulerian (ALE) method. The focus of this study is to highlight the difference in structural response between uncoupled and coupled Fluid Structure Interaction (FSI) numerical solution, and also to validate the ability of the FSI numerical simulation to solve complex problems, involving the generation and the propagation of water shock waves and their impact on the composite shell structures, using both multi-material ALE (MM-ALE) methods and advanced non-linear Fluid Structure Interaction (FSI) strong coupling algorithms. Results obtained from experiments are compared with numerical simulations using the LS-DYNA (R) software. The results are found to be in good agreement with the experimental data and are improved by considering the coupling effects, as the mass of the water acts as a viscous damper and reduces the high-frequency oscillations in the structural response

FSI of viscosity measuring mechanical resonators : theoretical and experimental analysis

Measuring viscosity online in processes is crucial to maintaining the quality of many chemical and biological processes. The damping induced by the liquid around the resonator is used to determine the viscosity of the liquids. Typical viscosity sensors are probe style and obstruct the piping system, disturbing the flow and creating a potential source of contamination in critical processes. The eventual goal is to design a non-intrusive sensor capable of accurately measuring the viscosity of the liquids without influencing the flow within the pipe. In order to get a deeper insight into the functionality of such a device, a mathematical model has been developed describing the mechanical vibration coupled with the fluid-structure interaction (FSI) models. The shear stresses at the wall have been analysed using the computational fluid dynamics tool OpenFOAM and have been integrated into the derived model. For validation, the model has been tested against the samples. The model is capable of accurately predicting the response of the sensor and can be used as an optimization and design tool

Application of a 2-D approximation technique for solving stress analyses problem in FEM

Published version. Source at http://doi.org/10.1260/1750-9548.9.4.317

Collaboration with Chinese Universities and My Research Portfolio

Academic presentation at Shandon Jianzhu University visit of Tromsø, 14.11.2023

CFD-DEM and Experimental Study of Bubbling in a Fluidized Bed

Publisher's version, source at http://dx.doi.org/10.1260/1757-482X.7.4.227.In this study, phenomenon of bubbling is investigated using CFD-DEM and experiments. A CFD-DEM simulation is setup to model the fluidized beds of different sizes. Geldart D particles of 1.2 mm diameter and 1000 Kg/m3 density are modelled. Study revealed different types of fluidization regimes as stated in the literature. An experimental setup is built to obtain the results for the comparison. Comparison revealed that results obtained from both methodologies; CFD-DEM and experiments are in reasonable agreement

Applicability Extent of 2-D Heat Equation for Numerical Analysis of a Multiphysics Problem

This work focuses on thermal problems, solvable using the heat equation. The fundamental question being answered here is: what are the limits of the dimensions that will allow a 3-D thermal problem to be accurately modelled using a 2-D Heat Equation? The presented work solves 2-D and 3-D heat equations using the Finite Difference Method, also known as the Forward-Time Central-Space (FTCS) method, in MATLAB®. For this study, a cuboidal shape domain with a square cross-section is assumed. The boundary conditions are set such that there is a constant temperature at its center and outside its boundaries. The 2-D and 3-D heat equations are solved in a time dimension to develop a steady state temperature profile. The method is tested for its stability using the Courant-Friedrichs-Lewy (CFL) criteria. The results are compared by varying the thickness of the 3-D domain. The maximum error is calculated, and recommendations are given on the applicability of the 2-D heat equation