When a shock interacts with a bubble having a different density than the environment or medium, the interaction causes compression and deformation of the bubble and generation of a vortex pair. Later, secondary vortices appear causing enhanced mixing. The enhanced mixing induced by the shock bubble interactions is particularly of interest in supersonic combustion and detonation. The Wavelet Adaptive Multi-resolution Representation (WAMR) method is particularly suitable for challenging continuum physics problems like shock bubble interaction, which has strong multi-scale character. This method provides an efficient strategy to create a dynamically adaptive spatial grid and to obtain a verified solution. Since the wavelet amplitude provides a first-hand estimate of the local error at each point, the method is able to efficiently capture a wide spectrum of spatial scales by dynamically changing the adaptive grid. Highly resolved computations are done only in the regions where abrupt transition occurs. In this work a detailed investigation of Shock Bubble Interaction (SBI) is carried out using shocks having Mach numbers from 1.2 to 3 for helium, nitrogen and krypton bubbles. Simulations carried out using WAMR method were used to analyze the effects of Mach number and density contrast on the shape, location and velocity of the bubble as well as vorticity and pressure in the flow field.

The Internet of Things (IoT) comprises many small, embedded devices that operate on severe resource constraints concerning energy, bandwidth, and memory footprints. Software for such devices has traditionally been implemented using relatively low-level languages such as C, which makes it susceptible to introducing bugs or flaws that can compromise the security of the device. This thesis adds interpreted WebAssembly (WASM) bytecode execution to Contiki-NG – an operating system for the next generation IoT devices. This is done using an open-source WASM runtime called WebAssembly Micro Runtime (WAMR). It creates an isolated and secure environment for applications to be executed in that has restricted access to the host operating system. To support the event-driven approach of Contiki-NG, the bytecode execution can be interrupted and resumed as needed, allowing the operating system to handle pending events without significant delays. The result is a way for applications written in a variety of programming languages to be safely executed in Contiki-NG and to interact with its APIs. When tested on Nordic Semiconductor's nRF52840 System-on-Chip (SoC), applications executed as bytecode resulted in an increase in binary size of 2.7-3.1x, and a performance penalty of around 9.2x for C-generated bytecode, and 10.3x for Rust-generated bytecode. For less compute-intensive applications, the performance penalty is not as prominent but still displays a sizable increase in energy consumption compared to native execution.