Abstract Compressors are a type of turbomachinery used to compress gases. The history of compressors an‎d compressed air dates back to ancient times. Compressors are used in various industries, including refineries, petrochemicals, power plants, etc. Compressors are divided into two groups in terms of performance: dynamic an‎d positive displacement. Dynamic compressors increase the kinetic energy of gas an‎d convert it into pressure energy. Positive displacement compressors increase the pressure of gas by reducing its volume. One type of dynamic compressor is axial flow compressors, which were originally developed for use in jet engines. This model of compressor consists of alternating rows of moving an‎d fixed blades. The moving blades are responsible for increasing kinetic energy, an‎d the fixed blades are responsible for directing the flow an‎d converting dynamic pressure into static pressure. These compressors are widely used in specific industries such as aerospace an‎d power plants due to their high output pressure, high mass flow rate, an‎d high efficiency in small volumes. Axial flow compressors also have disadvantages, the most important of which is the air back pressure gradient. Air return often starts from the distance between the moving blade tip an‎d the compressor shell (blade tip clearance), an‎d this initial separation of the air flow from the blade surface is called stall. If the separation of the air flow from the blade surface is complete, a surge occurs, which is accompanied by severe vibrations an‎d compressor failure an‎d must be prevented by control devices such as air discharge valves. According to the latest research conducted in the field of blade tip clearance, the best clearance size is half to two percent of the blade length. In continuation of the research conducted, in this study, in order to investigate the effect of different values of the distance between the moving blade tip an‎d the compressor shell under different operating conditions (rotational speed an‎d outlet static pressure), the three-dimensional geometry of a single-stage axial flow compressor was simulated using the powerful Ansys CFX software an‎d the characteristic curve an‎d optimal performance points were determined. Finally, it was concluded that the best design an‎d operating condition is for a compressor with a clearance of 1.5% of the blade length, a rotational speed of 22.000 rpm, an outlet static pressure of 0.96 atmospheres, an‎d an inlet mass flow rate of about 7.5 kg/s. These results can be used to optimize axial flow compressors used in industry.

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مصطفي نصيري , مرضيه رضازاده