Aerodynamic Optimisation of Turbocharger Compressor Diffuser Geometry for Real-World Drive Cycles (eBook)

Doctoral Thesis / Dissertation from the year 2022 in the subject Engineering - Automotive Engineering, grade: 8.0, Anglia Ruskin University (FACULTY OF SCIENCE & ENGINEERING), course: Mechanical Engineering, language: English, abstract: The aim of the dissertation is to develop a new numerical optimisation technique for the diffuser geometry of a typical turbocharger compressor, using a non-parametric optimisation method (adjoint). This leads to an increase in power and thermal efficiency in real-world drive cycles for passenger car engines. The geometry and experimental data correspond to the TD025-05T4 compressor from the 1.2-liter Renault Megane passenger car supplied by MTEE. In this study, a set of numerical simulations were conducted along two turbocharger compressor speed lines at 150,000 rpm and 80,000 rpm to analyse and validate the results against experimental data. Three points on each speed line are selected: one point each in regions close to surge and choke and a point in the stable zone of the compressor map. In addition, this study optimises the diffuser geometry in a passenger vehicle turbocharger compressor using a gradient-based solution approach employing a non-parametrical adjoint shaping optimisation for ideal gas turbulent compressible flow applications. The adjoint solver is a gradient-based optimisation that can automatically generate a series of iterations of a design so that the mesh gradually changes shape to meet a single goal, like the efficiency of the compressor in this case. The study considers a total of six operating cases on the compressor map to optimise the full and partial load compressor operations, leading to a real-world drive cycle. These cases are the three cases (closer to surge, stable midpoint, and closer to the choke point) on each of the speed lines. A typical result for mid-stable operation on a 150,000 (rpm) speed line shows a gradual increase in efficiency up to a maximum of 2.6% improvement. While, for choke and surge optimisation, the geometry variation of the optimised diffuser is different, in the stable central area for both speed lines, the geometry change is consistent. Therefore, the diffuser can be made to work best for both half and full load engine operation. As a result, the optimum diffuser geometry impacts engine efficiency and the overall performance of a typical passenger car for real drive cycles, increasing power and slightly improving thermal efficiency. When a typical car engine is running at full and half-load in real-world operation, the improved compressor efficiency is expected to make a small difference. This will make the engine more powerful and more efficient by about 0.1%.

I am an accomplished engineering professional with over 25 years of experience in both Italy and the UK. My expertise includes engineering design, lecturing, curriculum development, teaching, and research. I have a deep knowledge of machinery design and can create engineering drawings at all stages of a project, from concept through to commissioning. I have extensive practical experience working with a wide variety of industrial raw materials, such as aluminium, plastics, rubber, cast iron, and high-strength steel. Throughout my career, I have demonstrated a strong commitment to excellence, innovation, and continuous improvement. I am skilled in design calculations, finite element analysis, computational fluid dynamics, optimization, and fabrication design, and have applied these skills to a wide range of projects across different industries. In addition to my technical expertise, I have a passion for teaching and have developed and delivered engaging and effective curriculum for engineering students. I am a highly motivated individual with a proven track record of success, and I am always seeking new challenges and opportunities to grow and develop my skills. EXPERIENCE OVERVIEW Engineering Manager Project Engineer Senior Mechanical Design & Consulting Engineer Mechanical Design Engineer Mechanical Design and development Engineer 3D CAD technician Customer Support & Relations Lecturer in Mechanical Engineering Associate Lecturer Assistant Researcher Cover Supervision •Machinery Design - Detail, Assembly & Installation (Metric & British System) •Sheet Metal Design •Machining and fabrication Design •Proficient in Metric System as well as in British System •Finite Element Analysis (FEA) and CFD - Structural, Fluid and Heat transfer, Design sensitivity and optimisation, Mechanism and Contact non-linear analysis. Additionally, familiar with the most used materials in the industry as cast iron, steel and high strength steel, aluminium/magnesium and its alloys, rubbers as well as polymers and their derivatives (polypropylenes). In depth understanding of the physical properties as: - linear and nonlinear behaviour, fatigue behaviour - fatigue approach, life prediction and influence of temperature on material behaviour.