This paper presents the initial results of a model study to determine the heat-transfer characteristics of radial-flow gas turbines. A test facility was constructed and several unconventional experimental techniques were developed for use in the facility. An idealized model consisting of a shrouded rotating disk with a single radially inward airflow was studied. The flow pattern and heat-transfer behavior were analytically and experimentally determined. The experimentally determined heat transfer is correlated by an algebraic expression over the range of nondimensional parameters characteristic of radial-flow gas-turbine operation.