A wall assembly (60, 62) for use within a gas turbine engine, comprising: a multiple of liner panels (72, 74); and a support shell (68, 70) with a contoured region that forms a cavity between the support shell (68, 70) and at least one of the multiple of liner panels (72, 74); wherein: the contoured region extends toward a forward circumferential rail and an aft circumferential rail that extend from at least one of the multiple of liner panels (72, 74); and an intermediate circumferential rail of the at least one of the multiple of liner panels (72, 74) is between the forward circumferential rail and the aft circumferential rail; wherein the cavity is subdivided by the intermediate circumferential rail into a forward cavity that converges towards the forward circumferential rail and an aft cavity that converges towards the aft circumferential rail; wherein a multiple of cooling impingement passages penetrate through the support shell (68, 70) on each respective side of the intermediate circumferential rail; wherein a multiple of effusion passages penetrate through each of the liner panels (72, 74) and include a forward effusion passage and an aft effusion passage; wherein the forward cavity and the aft cavity accelerate and direct impingement airflow from the impingement passages towards the forward and aft effusion passages (108a, 108b). a multiple of liner panels (72, 74); and a support shell (68, 70) with a contoured region that forms a cavity between the support shell (68, 70) and at least one of the multiple of liner panels (72, 74); wherein: the contoured region extends toward a forward circumferential rail and an aft circumferential rail that extend from at least one of the multiple of liner panels (72, 74); and an intermediate circumferential rail of the at least one of the multiple of liner panels (72, 74) is between the forward circumferential rail and the aft circumferential rail; wherein the cavity is subdivided by the intermediate circumferential rail into a forward cavity that converges towards the forward circumferential rail and an aft cavity that converges towards the aft circumferential rail; wherein a multiple of cooling impingement passages penetrate through the support shell (68, 70) on each respective side of the intermediate circumferential rail; wherein a multiple of effusion passages penetrate through each of the liner panels (72, 74) and include a forward effusion passage and an aft effusion passage; wherein the forward cavity and the aft cavity accelerate and direct impingement airflow from the impingement passages towards the forward and aft effusion passages (108a, 108b). the contoured region extends toward a forward circumferential rail and an aft circumferential rail that extend from at least one of the multiple of liner panels (72, 74); and an intermediate circumferential rail of the at least one of the multiple of liner panels (72, 74) is between the forward circumferential rail and the aft circumferential rail; wherein the cavity is subdivided by the intermediate circumferential rail into a forward cavity that converges towards the forward circumferential rail and an aft cavity that converges towards the aft circumferential rail; wherein a multiple of cooling impingement passages penetrate through the support shell (68, 70) on each respective side of the intermediate circumferential rail; wherein a multiple of effusion passages penetrate through each of the liner panels (72, 74) and include a forward effusion passage and an aft effusion passage; wherein the forward cavity and the aft cavity accelerate and direct impingement airflow from the impingement passages towards the forward and aft effusion passages (108a, 108b).