A Combined Experimental and Theoretical Study of Flow and Pressure Distributions in a Brush Seal

Abstract

A relatively simple theory is presented which can be used to model the flow and pressure distributions in a brush seal matrix. The model assumes laminar, compressible, isothermal flow and requires knowledge of an empirical constant: the seal porosity value. Measurements of the mass flowrate together with radial and axial distributions of pressure were taken on a non-rotating experimental rig. These were obtained using a 122 mm bore brush seal with 0.25 mm radial interference. The experimental data are used to estimate the seal porosity. Measurements of the pressure distributions along the backing ring and under the bristle tips are discussed. Predicted mass flows are compared with those actually measured and there is reasonable agreement considering the limitations of the model.