the word conformal is a bit of a fuzzy meaning for the type of arrays you refer to. The term is used to describe an array that is flush with the hull of the submarine. it is not a bow array or spherical array. they usually run length-wise down the long axis of the sub. often called flank arrays.
The flank array or conformal array serves two purposes. narrowband identification and ranging. Heres how they work.
1. Identification. Low frequency sound travels further underwater. It also has the highest wavelength, meaning you need a really big array to pick it up. having a long array down the length of your boat does the trick. The towed array is a bit like a flank array, only you tow it behind you. these arrays are thin and long and dont detect broadband noise very well. So, you can use narrowband signals to ID your contacts. Towed arrays are much better at this, but flank arrays dont break and can operate in shallow water unlike towed sets.
2. comparing the data from your flank array to your another array can give you a better TMA and help your solution. so at short range they can act like little triagulators, your bow array gets one bearing and your flank another. you compare and get a rough range estimate. The Seawolf/Virginia Wide Aperature Array is a complete evolution of this. The wide flat arrays, placed along the hull give an almost 3 dimensional sonar picture with each array giving its own data.
some of you real sonar guys can correct me here. as for real-life washout speeds and performance I would either have to do some research or defer to an expert.
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