Our Gemara on Amud Aleph discusses the aspect of the burning of parts of the Sacrifices as providing a pleasant scent to G-d. What, in fact, does a Korban represent to G-d?  

The Torah often uses the phrase Reyach Nichoach, “A Pleasant Scent” in explaining what Hashem derives from the offering.  On the one hand, the reference to the term smell would seem to be the Torah’s way of distancing G-d from needing any sustenance, as smell is the most sublime and least physical of senses.  It would seem to be saying that Hashem derives a pleasure, but through the metaphor of smell it is the least tied to any physical benefit.  

I would like to add a neuroscientific peshat.  It is well known that odors have an unusual power to trigger memory.  We all have experienced a certain smell that can evoke a childhood memory or emotion in a manner far more effective than even a picture.  Recent advances in Neuroscience show this to be true within the brain structure as well.  While other senses are processed through the thalamus, a kind of switchboard, before they reach other parts of the brain, the olfactory bulbs are linked directly to the amygdala, the seat of emotions.  ( https://www.livescience.com/why-smells-trigger-memories.html )

Perhaps the Torah’s reference to korbanos as evoking a pleasant odor is to hint at the powerful nature of sacrifices, or even its present form in prayer.  Somehow, this kind of Avodah unlike any other mitzvah allows are more direct access to G-d’s “feelings”, His compassion and memory.  Thus, by the Torah referring to korbanos as providing a pleasant scent, it is hinting that we can influence G-d more directly and more powerfully, overcoming material barriers.