1Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow G1 1XH, United Kingdom
2School of Engineering, Institute for Multiscale Thermofluids, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh EH9 3JL, United Kingdom
3Department of Mathematical Sciences, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom