Aggregate sum multidimensional arrays grouped by name

I have an array as follows

Array
(
    [0] => Array
        (
            [operation_name] => test 1
            [capacity] => 180
        )

    [1] => Array
        (
            [operation_name] => Operation 2
            [capacity] => 251
        )

    [2] => Array
        (
            [operation_name] => Operation 2
            [capacity] => 241
        )

    [3] => Array
        (
            [operation_name] => Operation 3
            [capacity] => 554
        )

)

I want to sum the "capacity" key value of same "operation_name" key arrays and made it as a one array.

In the above array I need to sum the following 2 arrays,

    [1] => Array
        (
            [operation_name] => Operation 2
            [capacity] => 251
        )

    [2] => Array
        (
            [operation_name] => Operation 2
            [capacity] => 241
        )

And output the resulting array as below.

Array
(
    [0] => Array
        (
            [operation_name] => test 1
            [capacity] => 180
        )

    [1] => Array
        (
            [operation_name] => Operation 2
            [capacity] => 492
        )

    [2] => Array
        (
            [operation_name] => Operation 3
            [capacity] => 554
        )

)

How to do this with php?