Abstract: A method of thermodynamic assessment of flow through a turbomachine having a compressor, comprising: receiving sensor readings from a plurality of acoustic sensors located about an intake for the turbomachine upstream of the compressor; and receiving pressure and stagnation temperature readings for the flow into the intake. A static temperature is determined for the flow into the intake and an average velocity of the flow over a flow area of the intake upstream of the compressor using the acoustic sensor readings. A mass flow rate of the flow through the intake is determined using the average velocity of the flow and the stagnation pressure.

Abstract: A flow machine having a flow passage and an air flow measurement system comprising a plurality of acoustic sensors. The acoustic sensors comprise at least one acoustic transmitter configured to transmit an acoustic waveform through the airflow passing through the flow passage to an acoustic receiver. At least one of the acoustic sensors is rotatable relative to one or more other acoustic sensor.

Abstract: An aircraft includes a gas turbine engine and an optically-based measurement system. The gas turbine engine is configured to ingest a first mass flow and to exhaust a second mass flow. The optically-based measurement system is configured to determine the first and second mass flows in response to performing an imaging process on the gas turbine engine.

Abstract: A turbomachine having an air flow measurement system. The system comprises a plurality of acoustic sensors upstream a compressor of the turbomachine. The acoustic sensors comprise at least one acoustic transmitter configured to transmit an acoustic waveform through an intake airflow to an acoustic receiver. The acoustic sensors are located in a single plane and mounted at angular spacing about a central axis of an intake.

Abstract: A flow machine having a flow passage and an air flow measurement system comprising a plurality of acoustic sensors. The acoustic sensors comprise at least one acoustic transmitter configured to transmit an acoustic waveform through the airflow passing through the flow passage to an acoustic receiver. At least one of the acoustic sensors is rotatable relative to one or more other acoustic sensor.

Abstract: A method of thermodynamic assessment of flow through a turbomachine having a compressor, comprising: receiving sensor readings from a plurality of acoustic sensors located about an intake for the turbomachine upstream of the compressor; and receiving pressure and stagnation temperature readings for the flow into the intake. A static temperature is determined for the flow into the intake and an average velocity of the flow over a flow area of the intake upstream of the compressor using the acoustic sensor readings. A mass flow rate of the flow through the intake is determined using the average velocity of the flow and the stagnation pressure.