Is there a convention regarding frames around plots in engineering?

There is no convention or guide on this, at least none with appreciable universality. Having said that, one doesn't need a style guide for things like this.

The intention is to be clear to the reader. Minimalism or any other aesthetic ideal is secondary. In engineering, the values on graphs are potentially of interest, not just the trend. So a reader could potentially want to know the value of y(x), and your graph of y vs x should make it as easy as possible for him/her to do so. The top and right axes make it easier to read out values, because (a) you now have two sets of axes to check your value against, (b) a point on the top-right is as easy to read as a point on the bottom-left.

Given that, I wouldn't recommend removing the frame or the ticks on the frame.

In industry, you’ll often encounter branding guidelines around data visualization: fonts, colors, padding, margins, legends, etc. In academia, enforced adherence to branding guidelines is less common, particularly as an undergraduate. The exception is if you are presenting on behalf of the university or as part of your official role within the university. Even then, your institution may be happy with simply applying their logo to each slide. In terms of publishing research, every journal will have its guidelines that you need to apply to your articles layout and often the figures.

Now, in terms of the larger principles of data visualization, there are several go to figures. Perhaps the best known is Edward Tufte, who’s published a number of books, such as Visual Explanations. One of the ideas he’s contributed to is the maximization of the data-ink ratio (i.e. use the least amount of ink necessary to enable the data to ‘speak’).

In the context of your question, removing the frame is not a bad idea, in most cases they yield no utility. Removing axes entirely may be a bit aggressive. Removing unnecessary ticks and markers may be a nice middle ground. But those are just ideas; try exploring how the idea of a data-ink ratio can be put to use, it’s a fantastic tool.