CREATE TABLE table_1547951_3 (surface VARCHAR2, outcome VARCHAR2, championship VARCHAR2)

Name the surfaace where outcome is runner-up and championship is us open
SELECT surface FROM table_1547951_3 WHERE outcome = "Runner-up" AND championship = "US Open"
SELECT "surface" FROM "table_1547951_3" WHERE "Runner-up" = "outcome" AND "US Open" = "championship"