Apparatus and methods for acoustically determining internal characteristics of an engine and the like

A device for determining an internal performance characteristic of an engine during operation of the engine, the device comprising:

• vibration-detection means for receiving and detecting vibrations emanating from the engine during operation of the engine and for producing corresponding electrical signals based on the received and detected vibrations;
• memory means for storing pre-determined frequency data of vibrational emanations associated with the internal performance characteristic under various conditions;
• data-calculation means for receiving the electrical signals from the vibration-detection means, and for determining, from the received electrical signals, at least one diagnostic frequency of the vibrations;
• data-comparing means for comparing the determined diagnostic frequency with the pre-determined data in the memory means;
• and
• measurement-determination means for producing, based on the comparison performed by the data-comparing means, a measurement of the internal performance characteristic.

A device for controlling, in a combustor, a ratio between a fuel and an oxidizer substance used for producing combustion in the combustor, the device comprising:

• at least one acoustic-vibration detector configured to be situated relative to the combustor so as to receive and detect vibrations emanating from the combustor while combustion is occurring in the combustor, the at least one vibration detector being configured to produce corresponding electrical signals upon receiving and detecting the vibrations;
• a memory in which a data array is stored, the data array comprising frequency data of vibrational emanations associated with a particular internal-combustion characteristic of the combustor under various conditions;
• a computer coupled to the memory and to the at least one vibration detector so as to receive the electrical signals, the computer being configured (i) to determine, from the received electrical signals, at least one diagnostic frequency of the vibrations, (ii) to compare the calculated diagnostic frequency with the data array, (iii) to produce a measurement of the internal performance characteristic based on the comparison, and (iv) based on the measurement, determine a ratio between fuel and oxidizer substance in the combustor;
• and
• a feedback-control device coupled to the computer and to the combustor, the feedback-control device being configured to control, responsively to the ratio determined by the computer, supply of at least one of fuel and oxidizer substance to the combustor so as to regulate a condition of combustion of the fuel and oxidizer substance in the combustor.

A method for determining an internal performance characteristic of an engine during operation of the engine, the method comprising the steps of:

• detecting vibrations emanating from the engine during operation of the engine;
• producing electrical signals corresponding to the detected vibrations;
• determining from the electrical signals at least one diagnostic frequency of the vibrations;
• comparing the determined at least one diagnostic frequency with pre-existing data pertaining to frequency of vibrational emanations associated with the internal performance characteristic under various conditions;
• and
• producing a measurement of the internal performance characteristic based on the comparison.

A method for controlling an internal-combustion engine during operation of the engine, the method comprising the steps of:

• supplying a mixture of fuel and air to the engine as the engine is operating;
• detecting vibrations emanating from the engine during operation of the engine;
• producing electrical signals corresponding to the detected vibrations;
• determining from the electrical signals at least one diagnostic frequency of the vibrations;
• comparing the determined at least one diagnostic frequency with pre-existing data pertaining to frequency of vibrational emanations associated with the internal performance characteristic under various conditions;
• producing a measurement of the internal performance characteristic based on the comparison;
• and
• based on the measurement, changing a fuel-to-air ratio of the mixture being supplied to the engine.