Air guiding flap of an aircraft comprising control of the pressure forces impinging thereon, process for adjusting the position of an air guiding flap and ram air system including such an air guiding flap

The present invention relates to air guide flaps for aircraft, especially airplanes, and ram air devices including such air guide flaps. In particular, although the present invention relates to ram air exhaust flaps, the basic principles of the present invention are applicable to all air guide flaps.

Aircraft air guide flaps are exposed to strong aerodynamic forces, especially when the air guide flaps are located outside the aircraft and exposed to the wind pressure of relative airflow passing through the aircraft. This relates, for example, to the ram air exhaust flap of a ram air device that is part of a device that produces fresh air in an aircraft.

The fresh air that is pumped into the aircraft cabin introduces hot engine air, commonly known as bleed air, into the cooling air conditioning unit, which is then supplied to the aircraft cabin at the required temperature and pressure. It is created by that. Outside air is used as the cooling medium for the air conditioning unit, and this outside air flows into the ram air duct from the ram air intake flap placed on the aircraft during flight, and ram air is passed through this ram air duct to the air conditioning unit, and finally the ram air exhaust flap. From this ram air exhaust flap, warmer ram air is discharged from the aircraft. By changing the position of the ram air exhaust flap, the amount of cooling air passing through the air conditioning unit is controlled. If more cooling air is needed, the ram air exhaust flaps are forced to open more accordingly. After that, the intake port of the ram air duct is expanded by forcibly opening the ram air intake flap. Due to the expansion of the flow path cross section at the intake port of the ram air duct, more cooling air flows into the ram air duct and reaches the air conditioning unit. If less cooling air is required, the ram air exhaust flaps are first forced to close accordingly, followed by the ram air intake flaps of the ram air duct. Thus, this is so-called master-slave control, where the ram air exhaust flap is the "master" and the ram air intake flap is the "slave".

<p>The operation of such a ram air exhaust flap is characterized in that the stress changes significantly. When the ram air exhaust flap is forcibly opened wide, stress is applied by the external force (tensile force) caused by the aerodynamic pressure of the relative airflow. Conversely, if the ram air exhaust flap should be forced to open only slightly, it will only be stressed by the internal force (pressure force) provided by the flow of cooling air. These constantly changing and intense stresses during the operation of the aircraft cause repetitive problems with the functioning of the ram air exhaust flaps, which must be inspected regularly and repaired frequently.</p><p> To solve this problem, the ram air exhaust flap has recently been simply omitted, which reduces the manufacturing cost of the aircraft and avoids maintenance problems. However, maintaining capacity in this way requires the air conditioning unit to be more powerful, which results in the air conditioning unit being heavier and more expensive than when it actually requires a ram air exhaust flap. I will fall. In addition, omitting the ram air exhaust flap increases air resistance to the aircraft in operation, which in turn leads to an undesired increase in fuel consumption.</p><p> Another solution is to implement the ram air exhaust flap robustly enough to withstand all the pressure generated. However, in this case, the ram air exhaust flap is significantly heavier and more expensive than the conventional one, which leads to an increase in operating cost and manufacturing cost.</p><p> An object of the present invention is to use an air guide flap realized as a ram air exhaust flap, which has the advantage of the presence of the ram air exhaust flap, namely the reduction of air resistance of the aircraft and the potential performance improvement of the air conditioning unit. The solution is to solve the above problems so that they can be obtained without adversely affecting manufacturing and operating costs.</p><p>To achieve this object, the present invention confronts an air duct and provides one side exposed to the pressure generated in the air duct and the other side exposed to the pressure of the relative airflow passing through the aircraft. In the air guide flap of an aircraft, the air guide flap is provided with an actuator that automatically opens and closes the air guide flap, and the actuator is linked to a control device that controls the position of the air guide flap. A force detecting device for detecting a force applied to the actuator based on the difference between the pressure generated in the air duct and the pressure of the relative airflow passing through the aircraft is provided, and the position of the air guide flap is adjusted by the control device. However, the force applied to the actuator is set to be almost at least zero. In other words, the air guide flaps according to the invention are constantly adjusted to avoid excessive force exerted on the air guide flaps and are also provided by the pressure exerted on both sides of the air guide flaps, i.e., relative airflow on one side. Make sure that the kinetic pressure generated on the other side and the kinetic pressure generated in the duct on the other side cancel each other out. In this way, at all points of operation, the force exerted on the actuator will be small or absent at all. It should be understood that the actuator and the force applied to this actuator are not important and only the measurement of the force applied to the actuator is used as a measurement directly related to the stress of the air guide flap. Therefore, according to the present invention, the position of the air guide flap is controlled by the principle of aerodynamically balanced force.</p><p> Therefore, when the air guide flap thus implemented is used as a ram air exhaust flap of a fresh air generator for an aircraft, the above-mentioned problems described for such a device are solved. Therefore, in a preferred embodiment of the present invention, the air guide flap is the ram air exhaust flap, and the pressure in the air duct is the kinetic pressure. When the pressure applied to the ram air exhaust flap by the relative airflow passing through the aircraft becomes larger than the pressure applied to the ram air exhaust flap by the dynamic pressure in the air duct, both pressures are at least in an equilibrium state. The ram air exhaust flap is forcibly closed until</p><p> Regarding the above-mentioned preferred embodiment, in a more preferable embodiment, the air guide flap is also referred to as a ram air exhaust flap, and the pressure in the air duct is referred to as a kinetic pressure. When the pressure applied to the ram air exhaust flap by the relative airflow passing through the aircraft becomes smaller than the pressure applied to the ram air exhaust flap by the dynamic pressure in the air duct, both pressures are at least in an equilibrium state. The ram air exhaust flap is forcibly opened until</p><p>Further, in order to solve the above-mentioned problems, the present invention is a ram air device that supplies ram air to an auxiliary device of an aircraft, has a ram air duct having an air supply port and an exhaust port, and the auxiliary from the ram air duct. In a ram air device including a ram air air supply flap that takes in the ram air required for the device and controls the flow path cross section of the air supply port, and a ram air exhaust flap that controls the flow path cross section of the exhaust port. By opening and closing the ram air air supply flap, the amount of ram air required for the holding device is controlled, and the ram air exhaust flap is used as an air guide flap of any one of the above embodiments. ..</p><p> Regarding the above-mentioned ram air device, in a preferred embodiment of the present invention, the auxiliary device is an aircraft fresh air generator. Such a fresh air generator is used to pump fresh air into the aircraft cockpit and cabin to bring cabin pressure and temperature to predetermined values, in this case preferably controlling for the position of the ram air intake flap. The parameter is the temperature of the output of the compressor (sometimes referred to as an air wash box or turbo cooler) in a fresh air generator. In a preferred embodiment, this control forces the ram air air supply flap to open when the temperature at the output of the compressor of the fresh air device exceeds a predetermined temperature value. When the temperature at the output of the compressor of the fresh air device is equal to or lower than a predetermined temperature value, the ram air air supply flap is forcibly closed. The above-mentioned predetermined temperature value can be one same temperature value, but when one temperature value is exceeded, the ram air intake flap is forcibly opened, and when the temperature is lower than the other temperature values, the ram air intake flap is forcibly opened. It is also possible to close the ram air intake flap. Therefore, unlike the conventional standard procedure, the required amount of ram air is adjusted or controlled by changing the flow path cross section of the ram air duct intake port. When expanding the flow path cross section of the ram air duct intake port to increase the amount of ram air (by forcibly opening the ram air intake flap), increase the force of pressure applied to the surface of the ram air exhaust flap facing the ram air duct. become. To equilibrate the ram air exhaust flap with respect to the force applied to the ram air exhaust flap, the ram air exhaust flap is forcibly opened to reduce the airflow resistance through the ram air duct. The forced opening of the ram air exhaust flap is until the ram air exhaust flap is in equilibrium with respect to the force applied to the ram air exhaust flap, that is, at least due to the kinetic pressure in the ram air duct and the relative airflow from the outside to the ram air exhaust flap. Dynamic to join</p><p> On the other hand, if the amount of ram air passing through the ram air duct decreases, the ram air intake flap is forcibly closed accordingly. As a result, the kinetic pressure in the ram air duct is reduced, and the force applied to the inner surface of the ram air exhaust flap is also reduced accordingly. The ram air exhaust flap is forcibly closed until the aerodynamic pressure applied to the ram air exhaust flap is balanced. The forced closure of the ram air exhaust flap reduces the airflow resistance of the aircraft, which contributes to fuel savings.</p><p> Thus, in the most common embodiment of the invention, in a method of controlling the position of an aircraft air guide flap, at least the force of the aerodynamic airflow applied to both the inner and outer surfaces of the air guide flap is at least. The position of the air guide flap is controlled so as to reach an equilibrium state.</p><p> Hereinafter, examples of the present invention will be described in more detail with reference to the drawings.</p><p> As shown in Fig. 1, a fresh air generator that generates fresh air (fresh air) for an aircraft is shown. This fresh air device 10 is used to prepare the air to be supplied to the aircraft cabin. For this purpose, hot air from one or more engines in the aircraft (or even air from the aircraft's auxiliary turbine) is bleeded through the air intake 12 and introduced into the fresh air generator 10. .. The bleed air has a temperature of about 200 ° and is decompressed and cooled by the fresh air generator 10. The outside air that can be used as ram air during flight is used for the purpose of cooling, and this outside air can be supplied to the fresh air generator 10 by the ram air device 14.</p><p> The ram air device 14 has a ram air duct 16, a ram air duct intake port 18, and a ram air duct discharge port 20. In the case of the illustrated embodiment, the diffuser 22 arranged on the side of the ram air duct 16 distributes the ram air used as the cooling air to the surface of the heat exchanger of the fresh air generator 10 to cool the hot bleed air.</p><p> To reduce the additional air resistance of the aircraft generated by the ram air duct 16, the amount of cooling air passing through the ram air duct 16 during flight should always be kept as low as possible. The regulation of the amount of cooling air is part of the temperature controller of the fresh fresh air generator 10. The control parameter is the temperature at the compressor output of the fresh air generator 10, and during flight the compressor controls to a predetermined value, for example 180 ° C. When the compressor output temperature exceeds this predetermined value, the amount of cooling air flowing through the ram air duct 16 must increase. If the compressor output temperature falls below this value, the amount of cooling air must decrease.</p><p> A ram air intake flap 24 and a ram air exhaust flap 26 are provided for the purpose of controlling the amount of cooling air flowing through the ram air duct 16. With the ram air intake flap 24, the flow path cross section of the ram air duct intake port 18 can be changed from a value of 0 (closed position of the ram air intake flap) to the maximum value (open position of the ram air intake flap). Similarly, the flow path cross section of the ram air duct exhaust port 20 can be adjusted via the ram air exhaust flap 26.</p><p> The ram air exhaust flap 26 is located in or near the outer skin of the aircraft and faces the ram air duct 16 and has one inner surface 28 that is exposed to the aerodynamic pressure generated in the ram air duct 16. In addition, has an opposite outer surface 30 as an outer surface exposed to the pressure of relative airflow passing through the aircraft.</p><p> The actuator 32 can be used to change the position of the ram air air supply flap 24, and the position of the ram air exhaust flap 26 can be changed by the actuator 34.</p><p> When the compressor output temperature exceeds a predetermined value and requires more cooling air, the actuator 32 forcibly slightly opens the ram air air supply flap 24 to expand the flow path cross section of the ram air air supply port 18. .. More cooling air flowing into the ram air duct 16 through this expanded air inlet flow path cross section increases the kinetic pressure in the ram air duct 16 and the force acting on the inner surface 28 of the ram air exhaust flap 26. To do. In order to keep the stress of the ram air exhaust flap 26 having the actuator 34 as small as possible, the actuator 34 is provided with a force detection device 36, and the pressure generated by the force detection device 36 in the ram air duct 16 and the relative passage through the aircraft. The force applied to the actuator 34 is detected by the difference from the pressure of the air flow. The force detector 36 is connected to the control device, the ram air exhaust flap 26 is constantly adjusted to prevent high stress, and the pressure of the aerodynamic flow applied to the inner and outer surfaces 28 and 30 of the ram air exhaust flap 26. At least ensure that is in equilibrium. Therefore, more cooling air obtained through the more open ram air air supply flap 24 becomes the kinetic pressure in the ram air duct 16, and this kinetic pressure is applied to the outer surface 30 of the ram air exhaust flap 26. When it becomes larger than the relative air pressure, the ram air exhaust flap 26 is controlled to be forcibly opened until the force applied to the actuator 34 becomes zero, that is, until the forces are almost balanced. The forced opening of the ram air exhaust flap 26 reduces the flow resistance of the ram air duct 16 and, more precisely, the ram duct exhaust port 20, reducing the kinetic pressure of the ram air duct 16. At the same time, when the ram air exhaust flap 26 is forcibly opened, the pressure of the relative airflow passing through the ram air exhaust flap 26 increases so as to be applied to the outer surface 30 of the ram air exhaust flap 26.</p><p> On the other hand, when the compressor output temperature drops below a predetermined value, the amount of cooling air flowing through the ram air duct 16 must be reduced. This is caused by controlling the ram air air supply flap 24 to be closed, thereby reducing the flow path cross section of the ram air duct air supply port 18. The kinetic pressure of the ram air duct 16 is also reduced, and therefore the force exerted on the inner surface 28 of the ram air exhaust flap 26 is also reduced. In this way, the ram air exhaust flap 26 is forcibly closed and the force applied to the actuator 34 reaches at least near zero, which is the case on both the inner and outer surfaces 28 and 30 of the ram air exhaust flap 26. It means that the force is at least almost in equilibrium with the aerodynamic pressure applied to. Closing the ram air exhaust flap 26 also reduces the total resistance of the aircraft flow.</p><p> According to the fresh air generator 10 described above, the amount of cooling air required for this device can be controlled within a wide limit range, which has the effect of reducing the total resistance of the aircraft flow. Further, the ram air exhaust flap 26 controlled as described above has a low stress, which improves the reliability of operation and prolongs the life.</p>

<figref num="1">It is a perspective view of the fresh air generator of the aircraft which used the air guide flap by this invention which controls the position based on the method by this invention as an air exhaust flap.</figref><figref num="2">It is a schematic sectional view of the fresh air generator of FIG.</figref>