There are two criteria by which a successful search may be judged:
Precision and recall are inversely proportional - if you require high precision then you will have low recall but if you require high recall you will have low precision.
A literature review requires high recall and that requires different search strategy than a high precision search.
Can you describe your information need using one simple sentence or question?
Without a clear idea of the project, you may not be able to determine which are the best resources to search, what terminology should be used in those resources, and if the results are appropriate and sufficient.
If you're having difficulty getting your project described succinctly, try using a PICO chart to identify the concepts involved:
For a compressor cascade (P), what is the influence of free stream turbulence (I) on air flow (O)?
Can molecular modeling (I) be more cost effective (O) than lump modeling (C) for heavy oil refining (P)?
Does solar-power (I) produce enough energy (O) for running residential air-conditioning in desert climates (P)?
Searching within a resource is always a multi-part process:
A. Start with a P AND I search
B. Expand the P AND I search to include synonyms
C. Search using the database's controlled vocabulary for P AND I
D. Where do the C (comparison) and O (outcome) come into the search strategy?
E. For the most important documents you found, use citation searching to find even more: