In Focus: Stuart Moffatt reflects on one year at Stirling Dynamics

29/01/2021

Stuart Moffatt

Having reached a one-year milestone with Stirling Dynamics, we asked Principal Loads and Aeroelastics Engineer, Stuart Moffatt, to describe his first year with the company including what projects he has worked on and what a typical day is like.

I have recently completed my first year at Stirling Dynamics, where I work in the Structures and Fluid Mechanics group. Before joining the company, most of my experience has been in aerospace, with some time spent in energy and nuclear sectors, covering analysis, design and research and development. My main interest is in the interaction of structural mechanics and fluid dynamics in a range of engineering applications including propellers, helicopters, fixed-wing aircraft and gas turbines. For me, it is fascinating to understand how structures interact with fluid flow, where components can bend and twist due to pressures from the working fluid. To this end, I’ve developed software to predict how propeller blades bend during flight, designed helicopter blades that minimise vibration felt by passengers, and ensured rotor systems remain free from dangerous dynamic instabilities such as flutter.

I started my new role as a Principal Engineer at Stirling Dynamics in January 2020, so I got to spend a couple of months getting to know some of my colleagues in the new office before the UK lockdown started. Today, a typical day working from home during the COVID measures means that I start my day with project meetings to keep in touch with colleagues and up to date with project developments. It’s hard to believe it’s almost a year since I’ve been in the office and how well we’ve adapted to remote working. I sometimes forget that I have never met some of the people I work with! Home-schooling during lockdown means that I occasionally take a break from work and catch up later in the day; thankfully, Stirling Dynamics are very supportive towards family life and have been flexible.

A VARIETY OF PROJECTS

“On a technical level, I am very fortunate that project work at Stirling Dynamics is varied and reflects my interest in dynamic systems. Simulation of aircraft dynamics and landing gear structures is a major activity, together with the development of the software toolsets. My work has also spanned into the marine sector where my background in propellers has been useful in leading projects in propulsion systems”.

On a technical level, I am very fortunate that project work at Stirling Dynamics is varied and reflects my interest in dynamic systems. Simulation of aircraft dynamics and landing gear structures is a major activity, together with the development of the software toolsets. My work has also spanned into the marine sector where my background in propellers has been useful in leading projects in propulsion systems. I am currently leading a series of marine projects to support the design of a propulsion system for a naval vessel. A major challenge is to identify the methods and software tools to balance demands of modelling fidelity, timescales, and cost to meet evolving customer requirements through the programme. I was highly impressed with how quickly our engineers were able to build and run sophisticated 3D models of the ship structure and propulsion system using the latest Ansys software, which has come a long way since I last used Ansys as a postgraduate. This FE modelling work includes propeller strength assessment and the investigation of vibration characteristics of the shaft line and how resonant frequencies are affected by flexibilities in shaft bearings and supporting structures.

For the fluid dynamics, we have supplemented our own CFD capability with commercial propeller design software, enabling fast analysis turnarounds needed for evaluating propeller performance and how propeller flow interacts with the hull. Having a range of modelling tools is important for gaining confidence from improved insights from exploratory studies to detailed validation cases.

WheelTug is also another major project for me at present. WheelTug is developing an electric taxi system for the Boeing 737 and I am part of the Stirling Dynamic Loads team that is building dynamic simulation models of the aircraft to provide loading conditions used to demonstrate that the aircraft retains adequate strength and fatigue life. This last year has been extremely productive, supporting design and flight trials and working towards certification. What stands out for me, working on a complex project like this, is how capable and dedicated the team is and how much I can learn from them.

Next on the horizon are a few projects that will expand Stirling Dynamics’ capability in rotary aeromechanics for helicopters and propellers. I have spent most of my 20-year career in this area, so by combining my own experience with Stirling’s expertise in aerodynamics and structures, we can tackle some great opportunities that are arising in aerospace and marine sectors. Not only have we had interest from major multinational companies and institutions, but we are also getting involved in helping small technology start-ups get off the ground which is very rewarding.

Stirling Dynamics is currently recruiting in Systems Engineering, Software Engineering, Mechanical Design and Safety Engineering. For more information on our current vacancies visit: https://www.stirling-dynamics.com/careers/

Stuart Moffatt

Stuart is a Principal Engineer at Stirling Dynamics. Specialising in dynamic simulation and aeromechanics, Stuart supports analysis, design and certification activities in the aerospace and marine sectors.