Modelling of DPF regeneration using microwave energy

FEM based models in COMSOL multiphysics have been used to simulate regeneration of diesel particulate filter following the layout of an existing microwave cavity. The study utilized the physics packages in the software to model the electric field and thermal profiles of the microwave cavity and DPF. This was used to establish dimensions for microwave cavity and DPF. Further it was possible to integrate the heating properties of the Silicon Carbide used in the DPF substrate. The electric field and thermal profiles of the microwave cavity, as well as the DPF were investigated for the established dimensions and simulated results were compared with experiments. In the experiment, we deployed microwave power generated by a 2.45GHz magnetron into the existing microwave cavity to regenerate DPF. The results of the experiments showed the thermal profiles during DPF regeneration to be in agreement with the profiles from the simulated results. The scheme was further used to improve the design of the cavity for better energy utilization and DPF regeneration efficiency. Electric field and thermal profiles of the microwave cavity were established for various dimensions of microwave cavity for a given DPF size and the results were investigated. It was found that cylindrical cavity (diameter of 153mm and length of 533mm) gives the optimal dimensions for the regeneration of a commercial DPF (143mm (diameter) x 183mm (length) viewed in terms of near homogeneous electric field distribution.Authors wish to acknowledge InnovateUK for the financial support provided to the project ‘Marine Exhaust Gase Treatment System (MAGS) {grant reference number 42471-295209)’, in which, the presented work is part of

Precision tunable resonant microwave cavity

A tunable microwave cavity containing ionizable metallic vapor or gases and an apparatus for precisely positioning a microwave coupling tip in the cavity and for precisely adjusting at least one dimension of the cavity are disclosed. With this combined structure, resonance may be achieved with various types of ionizable gases. A coaxial probe extends into a microwave cavity through a tube. One end of the tube is retained in a spherical joint attached in the cavity wall. This allows the coaxial probe to be pivotally rotated. The coaxial probe is slideable within the tube thus allowing the probe to be extended toward or retracted from the center of the cavity

Hybrid Microwave-Cavity Heat Engine

We propose and analyze the use of hybrid microwave cavities as quantum heat engines. A possible realization consists of two macroscopically separated quantum dot conductors coupled capacitively to the fundamental mode of a microwave cavity. We demonstrate that an electrical current can be induced in one conductor through cavity-mediated processes by heating up the other conductor. The heat engine can reach Carnot efficiency with optimal conversion of heat to work. When the system delivers the maximum power, the efficiency can be a large fraction of the Carnot efficiency. The heat engine functions even with moderate electronic relaxation and dephasing in the quantum dots. We provide detailed estimates for the electrical current and output power using realistic parameters.Comment: 5 pages, 3 figures, final version as published in Phys. Rev. Let

Resonantly Tunable Majorana Polariton in a Microwave Cavity

We study the spectrum of a one-dimensional Kitaev chain placed in a microwave cavity. In the off-resonant regime, the frequency shift of the cavity can be used to identify the topological phase transition of the coupled system. In the resonant regime, the topology of the system can be controlled via the microwave cavity occupation and, moreover, for a large number of photons (classical limit), the physics becomes similar to that of periodically-driven systems (Floquet insulators). We also analyze numerically a finite chain and show the existence of a degenerate subspace in the presence of the cavity that can be interpreted as a \textit{Majorana polariton}.Comment: 11 pages, 6 figure