Abstract: A method and apparatus for acquiring aerodynamic noise of a compressor, a medium, and a product are provided. The method includes: performing inverse Fourier transform on a known frequency-domain noise spectrum to obtain known time-domain noise data, then predicting unknown time-domain noise using a time series neural network, obtaining finer time-frequency noise data in combination with the known time-frequency noise data, and finally, performing Fourier transform on the finer time-frequency noise data to obtain new frequency-domain noise data. Limitations of a limited time step and a total simulation time on the acquisition of aerodynamic noise data in traditional numerical calculation of aerodynamic noise can be overcome. Finer aerodynamic noise data can be acquired rapidly and accurately. The frequency resolution of the noise spectrum can be increased, and reducing the consumption of computing resources and saving manpower and material resources can be achieved.

Abstract: A method and apparatus for acquiring aerodynamic noise of a compressor, a medium, and a product are provided. The method includes: performing inverse Fourier transform on a known frequency-domain noise spectrum to obtain known time-domain noise data, then predicting unknown time-domain noise using a time series neural network, obtaining finer time-frequency noise data in combination with the known time-frequency noise data, and finally, performing Fourier transform on the finer time-frequency noise data to obtain new frequency-domain noise data. Limitations of a limited time step and a total simulation time on the acquisition of aerodynamic noise data in traditional numerical calculation of aerodynamic noise can be overcome. Finer aerodynamic noise data can be acquired rapidly and accurately. The frequency resolution of the noise spectrum can be increased, and reducing the consumption of computing resources and saving manpower and material resources can be achieved.

Abstract: A neural network-based method for predicting aerodynamic performance of a compressor of modeling design and a system therefor are provided. The method includes: constructing a data set; constructing a loss function, wherein the loss function is constructed based on a similarity modeling criterion; training a momentum-optimized neural network model according to the data set and the loss function to obtain an aerodynamic performance prediction model of the compressor of modeling design; predicting an aerodynamic performance of the compressor of modeling design by using the aerodynamic performance prediction model of the compressor of modeling design. According to the method, the momentum-optimized neural network model is trained by using the constructed data set and the loss function constructed based on the similarity modeling criterion, and the deep learning technology is applied to the aerodynamic performance prediction of the compressor of modeling design.

Abstract: Systems and methods are provided to generate an access code specific to a user of an online marketplace to use to enter a first accommodation during a first reservation time frame and a second accommodation during a second reservation time frame and to send the access code specific to the user to a computing device at the first accommodation and a computing device at the second accommodation to use to enter the first accommodation during the first reservation time period and the second accommodation during the second reservation time period. The access code is automatically removed from the computing device at the first accommodation and the computing device at the second accommodation at the end of the first reservation time period and at the end of the second reservation time period, respectively.

Abstract: A noise-reducing and nonuniform tip clearance structure of centrifugal compressor is provided, which includes a compressor impeller body and a compressor impeller shroud. The compressor impeller shroud is circumferentially wrapped outside the compressor impeller body, and multiple impeller blade bodies are uniformly arranged in a circumferential direction of the compressor impeller body. A clearance between an impeller tip meridian line of the impeller blade body and an impeller shroud meridian line on the compressor impeller shroud is an impeller tip clearance. The impeller tip clearance gradually decreases in a direction from a leading edge to a trailing edge of the impeller blade body, and a change rate of the impeller tip clearance in the direction from the leading edge to the trailing edge of the impeller blade body also gradually decreases.

Abstract: Systems and methods are provided to generate an access code specific to a user of an online marketplace to use to enter a first accommodation during a first reservation time frame and a second accommodation during a second reservation time frame and to send the access code specific to the user to a computing device at the first accommodation and a computing device at the second accommodation to use to enter the first accommodation during the first reservation time period and the second accommodation during the second reservation time period. The access code is automatically removed from the computing device at the first accommodation and the computing device at the second accommodation at the end of the first reservation time period and at the end of the second reservation time period, respectively.

Abstract: Provided is an intake bypass recirculation structure capable of silencing, including: an intake bypass recirculation structure body and a structure-conducted silencing device. An intake bypass recirculation cavity is provided on the intake bypass recirculation structure body. An inlet of the intake bypass recirculation structure and an outlet of the intake bypass recirculation structure that are provided on the intake bypass recirculation structure body are each connected to the intake bypass recirculation cavity. The structure-conducted silencing device is disposed inside the intake bypass recirculation cavity. In this application, during working, noise generated by a compressor is transmitted into the intake bypass recirculation cavity via an inlet of the intake bypass recirculation structure, and transmitted outside via the outlet of the intake bypass recirculation structure.

Abstract: Some embodiments of the disclosure provide an air intake bypass recirculation structure with adjustable air entraining amount and controllable broadband noise which includes main body of the air intake bypass recirculation structure and an air entraining amount adjusting structure. In some examples, an air intake bypass recirculation cavity is formed in the main body of the air intake bypass recirculation structure. An air inlet of an air intake pipe and an air outlet of the air intake pipe are formed in two ends of the main body of the air intake bypass recirculation structure respectively. An airflow inlet of the air intake bypass recirculation structure and an airflow outlet of the air intake bypass recirculation structure are formed in the inner side of the main body of the air intake bypass recirculation structure. The air entraining amount adjusting structure is arranged in the air intake bypass recirculation cavity.

Abstract: A turbocharger air intake silencer with adjustable cavity space structures is provided. The turbocharger air intake silencer comprises a silencer connecting flange and a first resonator device. The first resonator device comprises a first silencer sealing plate, a first annular sound absorption cavity body, a first rotary table, a first rotary steering gear and a first valve. A first sound absorption cavity is enclosed by the first silencer sealing plate, the first annular sound absorption cavity body, the first valve and the first rotary table. A first sound absorption cavity inlet pipe is arranged beside the first sound absorption cavity. The first sound absorption cavity and the first sound absorption cavity inlet pipe form a Helmholtz resonator. The first rotary steering gear is mounted on the silencer connecting flange. The rotary steering gear is connected with a first rotary rack.

Abstract: Some embodiments of the disclosure provide an air intake bypass recirculation structure with adjustable air entraining amount and controllable broadband noise which includes main body of the air intake bypass recirculation structure and an air entraining amount adjusting structure. In some examples, an air intake bypass recirculation cavity is formed in the main body of the air intake bypass recirculation structure. An air inlet of an air intake pipe and an air outlet of the air intake pipe are formed in two ends of the main body of the air intake bypass recirculation structure respectively. An airflow inlet of the air intake bypass recirculation structure and an airflow outlet of the air intake bypass recirculation structure are formed in the inner side of the main body of the air intake bypass recirculation structure. The air entraining amount adjusting structure is arranged in the air intake bypass recirculation cavity.

Abstract: A turbocharger air intake silencer with adjustable cavity space structures is provided. The turbocharger air intake silencer comprises a silencer connecting flange and a first resonator device. The first resonator device comprises a first silencer sealing plate, a first annular sound absorption cavity body, a first rotary table, a first rotary steering gear and a first valve. A first sound absorption cavity is enclosed by the first silencer sealing plate, the first annular sound absorption cavity body, the first valve and the first rotary table. A first sound absorption cavity inlet pipe is arranged beside the first sound absorption cavity. The first sound absorption cavity and the first sound absorption cavity inlet pipe form a Helmholtz resonator. The first rotary steering gear is mounted on the silencer connecting flange. The rotary steering gear is connected with a first rotary rack.

Abstract: Systems and methods are provided to generate an access code specific to a user of an online marketplace to use to enter a first accommodation during a first reservation time frame and a second accommodation during a second reservation time frame and to send the access code specific to the user to a computing device at the first accommodation and a computing device at the second accommodation to use to enter the first accommodation during the first reservation time period and the second accommodation during the second reservation time period. The access code is automatically removed from the computing device at the first accommodation and the computing device at the second accommodation at the end of the first reservation time period and at the end of the second reservation time period, respectively.