A sensor support portion supports a physical quantity sensor. A flow path housing portion forms a measurement flow path, which accommodates a support tip end portion of the sensor support portion. The sensor support portion includes a support front surface, which includes a front fixed portion away from the support tip end portion and fixed to an inner surface of the flow path housing portion. The physical quantity sensor includes a sensor exposure surface exposed from the support front surface. A separation distance between an end portion of the front fixed portion and an end portion of the sensor exposure surface is smaller than a separation distance between the end portion of the sensor exposure surface and the support tip end portion.

A measurement control device includes a sensing unit and a low-pass filter unit. The sensing unit outputs an air flow rate value corresponding to an air flow rate flowing through a flow path. The low-pass filter unit removes high-frequency components included in the air flow rate value input from the sensing unit. The measurement control device calculates a pulsation state that is a state of a pulsation occurring in the air flow rate based on the air flow rate value that has passed through the low-pass filter unit. The measurement control device corrects the air flow rate value using the pulsation state.

An air cleaner has a body, an intake part to take air into the body, an exhaust pipe to exhaust the air from the body, a mounting section to mount an air flow meter to the exhaust pipe, a rib disposed on an inner surface of the body, and a straightening element disposed on an inner surface of the exhaust pipe. The rib extends toward the exhaust pipe and the straightening element extends in a same direction where the rib extends. The straightening element is located closer to the body than the mounting section.

Methods and systems are provided for pinpointing a source of degradation in a vehicle engine system. In one example, a method includes spinning an engine of a vehicle unfueled in a forward and a reverse direction, in no particular order, and recording a first intake air flow and a second intake air flow, respectively, in an intake of the engine, and where the source of degradation is indicated as a function of both the first air flow and the second air flow. In this way, the degradation of the vehicle engine system may be pinpointed as to being located in the intake manifold, the exhaust system, or the engine.

An air intake system (100″) for vehicle is provided. The air intake system (100″) includes an air filter assembly (108), and an air conduit (101). The air filter assembly (108) includes a first part mounted to a frame of the vehicle, and a second part mounted to a chassis of the vehicle. The first part and second part are arranged in such a manner that the attachment of the frame and the chassis together causes assembly of the first part and second part of the air filter assembly (108). The air conduit (101) includes an inlet end (103) and an outlet end (105), and coupled to a turbocharger. The air conduit (101) extends horizontally between the inlet end (103) and the outlet end (105) and comprises a plurality of segments such that a first segment bends at predefined angles to couple to a second segment of the plurality of segments.

A method for controlling a speed of a turbocharger that is in operative connection with a compressor, the steps including: provision of a setpoint for the speed of the turbocharger on the basis of a model-based precontrol for a calculation of a desired boost pressure ahead of the turbocharger; determination of an actual value for the speed of the turbocharger; control of an actuator of the turbocharger in order to compensate for the difference between the desired value and the actual value for the speed of the turbocharger. A main signal and a subsidiary signal are provided during the determination of the actual value for the speed of the turbocharger, wherein the main signal and the subsidiary signal are combined in order to validate the actual value for the speed of the turbocharger.

A self-calibration method of determining remaining useful life of an internal combustion engine's air filter includes establishing a pressure drop versus mass airflow rate relationship for a clean air filter using pressure drop, mass airflow rate, and temperature data captured at low and elevated engine speeds. The method also includes establishing a maximum clean air filter pressure drop at a preset maximum airflow using the clean filter relationship. The method additionally includes establishing a pressure drop versus mass airflow rate relationship for an in-service air filter using pressure drop, mass airflow rate, and temperature data captured at low and elevated engine speeds. The method also includes determining a maximum in-service air filter pressure drop at the preset maximum airflow using the in-service filter relationship. The method further includes comparing the maximum clean and in-service air filter pressure drops to determine the remaining useful life of the in-service air filter.

A method of optimizing engine air-mass-flow intake of an aircraft includes determining air mass flow (“M1”) at a forward-facing airframe inlet duct. The forward-facing airframe inlet duct includes an air-mass-flow bypass mechanism. The method also includes determining required air mass flow (“MR”) of an engine coupled to the forward-facing airframe inlet duct, determining an air-mass-flow difference (“M3”) between M1 and MR, and adjusting the air-mass-flow bypass mechanism to pass M3 such that at least a portion of M3 does not reach the engine.

An air induction system includes an air duct and an air permeable membrane. The air duct is configured to deliver intake air to an engine. The air duct includes a cylindrical wall defining a bore and an enclosure projecting from an outer radial surface of the cylindrical wall and defining a cavity therein. The cylindrical wall has an opening extending therethrough that enables airflow from the bore to the cavity in the enclosure. The air permeable membrane is configured to cover the opening in the cylindrical wall.

An air intake amount measurement device 200 includes an intake distributor 3 distributing intake air CYL to cylinders 11, 12, 13, and 14, a temperature detector 202 detecting a temperature Ti of the intake air CYL, a pressure detector 201 for detecting a pressure Pi of intake air CL, and a computing unit 100 that computes an air intake amount mfcyl of the intake air CYL on the basis of the temperature Ti transmitted from the temperature detector 202 and the pressure Pi transmitted from the pressure detector 201. The temperature detector 202 detects the temperature Ti of the intake air CYL at a region W spanning, out of an inside of the intake distributor 3, a first branch portion 31 and a second branch portion 32.