# US 10,371,618 B2 · Maximum filter flow predictor

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,371,618 B2
- Document ID: US10371618B2
- Status: Granted
- Kind: B2
- Application number: 14/844,865
- Filed: 2015-09-03
- Published: 2017-03-09
- Granted: 2019-08-06
- Earliest claimed: 2015-09-03
- Assignees: Bell Helicopter Textron Inc.
- Applicants: Bell Helicopter Textron Inc.
- Inventors: Alan H. Steinert
- Web page: https://patentgrep.com/patent/US10371618B2

## CPC

- G01N 15/0826: {and measuring fluid flow rate, i.e. permeation rate or pressure change}
- B64C 27/14: Direct drive between power plant and rotor hub
- B64D 33/02: of combustion air intakes
- B64D 45/00: Aircraft indicators or protectors not otherwise provided for
- B01D 46/0086: {Filter condition indicators}
- B01D 2279/60: for the intake of internal combustion engines or turbines
- B64C 27/04: Helicopters
- B64D 2033/0246: {comprising particle separators}
- B64D 2045/0085: {Devices for aircraft health monitoring, e.g. monitoring flutter or vibration}
- G01N 2015/084: {Testing filters}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- B64C: AEROPLANES; HELICOPTERS
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

In one example embodiment, a filter condition measurement device features an engine data repository, one or more sensor units, and a measurement unit. The measurement system is configured to identify a first flow value corresponding to a sensed engine power value from the engine data repository, determine a filter coefficient for the filter as a function of the first flow value and the sensed delta-pressure value; identify a second engine power value from the plurality of stored engine power values and a second flow value corresponding to the second engine power value; and determine a second delta-pressure value for the air filter as a function of the filter coefficient and the second flow value.

## Claims

### Claim 1

A filter condition monitoring system, comprising:
an engine data repository configured to store an engine data set comprising a plurality of stored flow values and a plurality of stored engine power values corresponding to the plurality of stored flow values;
one or more sensor units configured to receive, during operation of an aircraft having an engine and an associated air filter with an inlet and an exhaust, a sensed delta-pressure value and a sensed engine power value corresponding to the sensed delta-pressure value, the sensed delta-pressure value representing a difference in pressure between the inlet and the exhaust of the air filter;
a measurement unit configured to:
identify a first flow value corresponding to the sensed engine power value from the engine data repository;
determine a filter coefficient for the filter as a function of the first flow value and the sensed delta-pressure value;
identify a second engine power value from the plurality of stored engine power values and a second flow value corresponding to the second engine power value; and
determine a second delta-pressure value for the air filter as a function of the filter coefficient and the second flow value; and
a filter condition indicator configured to provide an indication representative of the second delta-pressure value.

### Claim 2 (depends on 1)

The filter condition monitoring system of claim 1, the measurement unit comprising a processor configured to determine a maximum delta-pressure value for the air filter and to store the maximum delta-pressure value for the air filter in one or more memory locations associated with the engine data repository.

### Claim 3 (depends on 1)

The filter condition monitoring system of claim 1, wherein:
the second engine power value is a maximum engine power value representing the highest engine power value achievable by the engine; and
the second delta-pressure value is a maximum delta-pressure value representing a prediction for what the delta-pressure value would be if the engine operated at the maximum engine power value.

### Claim 4 (depends on 1)

The filter condition monitoring system of claim 1, wherein the filter condition indicator is an audible or visual alert configured to provide an alert if the second delta-pressure value fails to satisfy a predetermined criterion.

### Claim 5 (depends on 1)

The filter condition monitoring system of claim 1, further comprising a display, wherein the filter condition indicator comprises a visual indication on the display representative of the second delta-pressure value.

### Claim 6 (depends on 1)

The filter condition monitoring system of claim 1, wherein the plurality of stored engine power values comprises power values generic to a category of engines.

### Claim 7 (depends on 1)

The filter condition monitoring system of claim 1, wherein the plurality of stored engine power values comprises a first plurality of power values generic to a category of engines and a second plurality of power values specific to an individual engine.

### Claim 8 (depends on 1)

The filter condition monitoring system of claim 1, further comprising an air filter bypass mechanism configured to bypass the air filter in response to the second delta-pressure value failing to satisfy a predetermined criterion.

### Claim 9

A rotorcraft, comprising:
a body;
a power train coupled to the body and comprising one or more power sources, a drive shaft coupled to the one or more power sources, and an air filter with an inlet and an exhaust associated with the one or more power sources;
a rotor system coupled to the power train comprising a plurality of rotor blades; and
a filter condition measurement device at least partially disposed within the body, the filter condition measurement device comprising:
an engine data repository configured to store an engine data set comprising a plurality of stored flow values and a plurality of stored engine power values corresponding to the plurality of stored flow values;
one or more sensor units associated with the power train and configured to receive, during operation of the rotorcraft, a sensed delta-pressure value and a sensed engine power value corresponding to the sensed delta-pressure value, the sensed delta-pressure value representing a difference in pressure between the inlet and the exhaust of the air filter;
a measurement unit configured to:
identify a first flow value corresponding to the sensed engine power value from the engine from the engine data repository;
determine a filter coefficient for the filter as a function of the first flow value and the sensed delta-pressure value;
identify a second engine power value from the plurality of stored engine power values and a second flow value corresponding to the second engine power value; and
determine a second delta-pressure value for the air filter as a function of the filter coefficient and the second flow value; and
a filter condition indicator configured to provide an indication representative of the second delta-pressure value.

### Claim 10 (depends on 9)

The rotorcraft of claim 9, wherein the filter condition indicator is an audible or visual alert configured to provide an alert if the second delta-pressure value fails to satisfy a predetermined criterion.

### Claim 11 (depends on 9)

The rotorcraft of claim 9, further comprising a display, wherein the filter condition indicator comprises a visual indication on the display representative of the second delta-pressure value.

### Claim 12 (depends on 9)

The rotorcraft of claim 9, further comprising an air filter bypass mechanism configured to bypass the air filter in response to the second delta-pressure value failing to satisfy a predetermined criterion.