Whirlwind is to put it simply... bad, no one expect the D2 whirlwind but the one we have here is just plain bad.
even more useless in higher difficulty where exposing yourself in contact range with the enemy without doing high damage or life replenishing from them quickly is essentially suicide.
and on "What of inferno with barbarian??"
you will not survive inferno with barbarian in general until you get massively decked out
with my barbarian sitting at 70% armor mitigation and 65% resist all around (some higher like physical than others) i can handle most of the regular mobs in act 1 inferno. (bosses are ridiculously weak, like leoric or butcher, even on inferno)
however most champions and elites with bad mix will still pulverize me, that includes:
jailer, desecrate, arcane enchanted, vampiric, illusionist, invulnerable minions, mortar
take any combinations of 3 of the above on a champion/elite, and your barbarian hope of killing them in Act 1 even is essentially single digit percentage with most builds except for ranged build.
Bosses are not a problem in general, but any one of the champions/elites in the way with bad mix? Well, you either bypass them somehow or you reset and pray for a better one next time or if you are feeling patient you chip them maybe killing the minions first for each live you have and respawn continuously till it dies (yeah it's going to be one hell of an expensive venture).
Act 2 is out of the question for melee if you can't handle Act 1 comfortably since the difficulty jump between Act 1 and Act 2 is essentially like a separate difficulty level in itself. Belial's serpent minions that you fight regularly in Act 2 alone hits for 5 digit damage unmitigated (almost 6 digit) from single hit of their skills and since your armor and resist is even less effective than in Act 1 thanks to their higher level in Act 2 you take even more massive damage.
i am farming Act 3 to an extent but i can't say i am fighting them effectively with my barbarian, rather i am just exploiting their AI before they fix it.
My current build is in fact ranged, but uses neither the spear or the axe throw...