Matching tests of an aircraft inlet and engine on the ground in our test cell have been performed.By means of the measuring rake/ring device which consists of 40 total pressure probes and 20 circumferentially located bundles of three tube probes

the total pressure distribution and the airflow speed distribution at the exit plane of the inlet were obtained.On the basis of the test data

we computed the stable pressure distortions in circumferential and diametric directions.The regular changing patterns of these distortions with the variations of the airflow rate into the engine were thus obtained.The circumferential rotational flow and pair whirls at the exit of the inlet were also found

and subsequently

the causes were analyzed.In addition

main performance parameters of the engine were measured

such as thrust

exhaust gas temperature and their changes after the inlet of the aircraft was installed.The causes of the changes were also analyzed.