Which template should I use for a journal methodology section?

The short answer is that there isn't one universal template, but the absolute best framework you can use is a published article from your target journal. Since you are on a tight two-week deadline, your quickest path to success is to download three recent papers from that exact journal that use a similar methodology to yours. Think of these papers as your custom-built blueprints. You can reverse-engineer their structure, looking at how they organize their subsections, how they describe their materials, and what level of technical detail they include to satisfy the reviewers. I completely understand how stressful it is to face a blank page with a looming deadline, especially when your supervisor expects perfection but leaves you without a map. It feels a bit like being asked to bake a complex soufflé without a recipe. To get this done in two weeks, start by breaking your methods into chronological steps: what you used, how you set up the experiment, and how you analyzed the data. Write a quick, messy draft of these steps first without worrying about perfect grammar, and then use your target journal's papers to polish the tone and formatting. Since this is engineering, focus heavily on reproducibility by including specific model numbers, software versions, and precise flow rates or temperatures. If you structure your section to mirror the successful papers you found, you will naturally match the journal's style and meet your supervisor's high standards. You have got this, so just take it one subsection at a time and you will easily make that submission deadline.