The understanding of heat transfer and fluid motion in compressor rotor drums is a key know-how for the design and analysis of highly loaded and efficient aeroengines. Since rotor blade tip clearance depends on the thermal growth of the disks, the accurate prediction of the temperature and Nusselt number distribution of these structures is crucial for the turbomachinery performance. Historically the calculation of heat transfer coefficients was done with respect to the inlet temperature of the air entering the cavity. This could lead to misinterpretation of local effects. Therefor, accurate measurements of air and metal temperatures can shed light on the phenomena that impact the disk heat transfer. This paper presents the results of a single cavity rig that consists of a pair of identical disks, a cylindrical shroud and a stationary inner shaft. The disks and the shroud of the rig can be heated individually to generate an axial gradient to the cavity as found in real engines. Disk and fluid temperature as well as static pressure measurements of the cavity are carried out by a two-sided telemetry system. A new calculation method for the core-swirl ratio distribution from static pressure measurements inside the cavity is presented and compared to laser Doppler anemometry (LDA) investigations from previous work. The operating conditions cover a wide range of cases that are representative of typical high pressure compressor operation. There are additionally new test conditions with asymmetric heating on the outer surface of the cavity.