As a follow on to my earlier answer, you can find Whitman concentrating on smell in section 2 of “Song of Myself”: the “houses and rooms” are full of ”perfumes,” but to Whitman the ”atmosphere“ is more alluring; while he does not let the perfumes intoxicate him, the air does:

It is for my mouth forever, I am in love with it,

I will go to the bank by the wood and become undisguised and naked,

I am mad for it to be in contact with me.

Whitman is a very concrete poet, in that he always grounds his poetry in sensory experience. It’s hard to find a place in Whitman that does not contain vivid imagery. There is his famous image of the grass as “the beautiful uncut hair of graves,” for example; here he conflates the ordinary, grass, with an image of corpses under the earth growing their hair out. It’s at once beautiful, and disturbing, and expresses Whitman’s sense of the connectedness of all things, that even in death we continue to be part of the world, engaged in creating beauty.

Whitman’s poetry is intensely visual, but he hardly ignores the other senses. Take this stanza from “In Cabin’d Ships at Sea,” in which Whitman “sends” his poem out onto the ocean, as if it itself were a ship:

Here are our thoughts, voyagers' thoughts,
Here not the land, firm land, alone appears, may then by them be said,
The sky o'erarches here, we feel the undulating deck beneath our feet,
We feel the long pulsation, ebb and flow of endless motion,
The tones of unseen mystery, the vague and vast suggestions of the briny world, the liquid-flowing syllables,
The perfume, the faint creaking of the cordage, the melancholy rhythm,
The boundless vista and the horizon far and dim are all here,
And this is ocean's poem.

Whitman evokes here the experience of being at see on a sailing ship; the bold selections indicate some of the places where he invokes sight, sound, and smell. You can feel the movement of the ship when you read these words, and hear the sounds of the rigging. I particularly like the phrase “liquid-flowing syllables,” another one of his incredibly compact and efficient images—he‘s talking about the sound of the water as the ship cuts through it, but the image suggests that this sound itself is a kind of language, or poetry.

You can find such examples, as I said, almost everywhere in his poetry. In fact, I would say that part of Whitman’s allure is his intense imagery, which the reader comes to take for granted, perhaps.

In part 5, Whitman writes,

Loafe with me on the grass, loose the stop from your throat,
Not words, not music or rhyme I want, not custom or lecture, not even the best,
Only the lull I like, the hum of your valved voice.

The first image, in bold above, is a tactile one: one can imagine the feel, the touch, of the grass as one lies down on it. The second image, in bold above, is auditory: one can hear the hum of a beloved's voice, especially in contrast with the other human noises Whitman describes.

Whitman also describes one who "reach'd till [they] felt [his] beard, and reach'd till [they] held his feet." This is another example of a tactile image (touch).

Later, Whitman writes,

limitless are leaves stiff or drooping in the fields,
And brown ants in the little wells beneath them,
And mossy scabs of the worm fence, heap'd stones, elder, mullein, and poke-weed.

Above, we are presented with several visual images, all of which describe things that we might see. Whitman describes the leaves, the ants, and the plants.

In part 6, Whitman describes a child who asks about the grass and then "fetch[es] it to [him] with full hands." This could also be described as a visual or tactile image. Later, he likewise describes the grass as

Sprouting alike in broad zones and narrow zones,
Growing among black folks as among white . . .
And now it seems to me the beautiful uncut hair of graves.

This constitutes another series of visual images: the "sprouting," and the different colors of people, as well as the metaphor comparing the grass to grave hair.

Imagery is all over the place in Whitman's "Song of Myself," and that imagery appeals to a wide range of the senses. Here are some quick examples from section 2:

Sight: "The play of shine and shade on the trees as the supple boughs wag"

Sound: "The sound of the belch'd words of my voice loos'd to the eddies of the wind"

Touch: "A few light kisses, a few embraces, a reaching around of arms"

Smell: "Houses and rooms are full of perfumes, the shelves are crowded with perfumes, / I breathe the fragrance myself and know it and like it, / The distillation would intoxicate me also, but I shall not let it."

Taste: "The atmosphere is not a perfume, it has no taste of the
distillation, it is odorless, / It is for my mouth forever, I am in love with it"

Those examples are all from just one short section of the poem! Imagery is all over the place in Whitman's "Song of Myself." He definitely philosophizes and deals in abstract ideas in his poetry, but he always seems to bring things back to the level of concrete, sensory details.