CN111896211B - A partition interpolation method for five-hole probes under large inflow angles - Google Patents

Abstract

The invention provides a subarea interpolation method for a five-hole probe under a large inflow angle, which includes acquiring an inner-area interpolation file and an outer-area interpolation file; acquiring the five-hole pressure value collected by the five-hole probe, and determining according to the five-hole pressure value Interpolation partition mode, the interpolation partition mode is divided into inner region mode and outer region mode; when the interpolation partition mode is inner region mode, the pressure value of the five holes is processed based on the inner region interpolation file, and the flow field is obtained. Total pressure and static pressure; when the interpolation partition mode is the outer zone mode, the five-hole pressure values are processed based on the outer zone interpolation file to obtain the total pressure and static pressure of the flow field; the total pressure and static pressure based on the flow field Calculate the flow velocity of the flow field. When the incoming flow angle of the probe is too large, the air flow in the part of the probe will be separated from the boundary layer, and the pressure-sensing hole in the separation area will fail, resulting in inaccurate measurement. By adopting the method of the present invention, the above problems can be overcome, and the range of the incoming flow angle adapted to the probe is increased from ±30° to ±45°.

Description

A partition interpolation method for five-hole probes under large inflow angles

technical field

The invention relates to the field of wind tunnel engineering measurement, in particular, to a subarea interpolation method of a five-hole probe under a large incoming flow angle.

Background technique

As a flow field measurement tool, the five-hole probe is widely used in the plane cascade wind tunnel experiment. Using the traditional interpolation method can only measure the air flow within ±30° of the incoming flow. When the incoming flow angle is too large, the air flow in the part of the probe will be separated from the boundary layer, and the pressure-sensing holes in the separation area will fail, resulting in Inaccurate measurement. Under the condition of high angle of attack in the related experiments of the plane cascade, due to the severe separation of the boundary layer behind the cascade, the change of the airflow vector is large. In particular, the flow in the angular region of the flow field behind the grid is very complex. In addition to the drastic change of Mach number, the angular change of the airflow is also very large, which has exceeded the measurement range of traditional interpolation methods. In view of this situation, a partition interpolation method is proposed.

SUMMARY OF THE INVENTION

According to the technical problem of inaccurate measurement caused by the above-mentioned large angle of attack working conditions exceeding the existing interpolation measurement range, a partitioned interpolation method of five-hole probe under large incoming flow angle is provided. inflow angle.

The technical means adopted in the present invention are as follows:

A partition interpolation method for a five-hole probe under a large inflow angle, comprising:

Get the inner area interpolation file and the outer area interpolation file;

acquiring the five-hole pressure value collected by the five-hole probe, and determining an interpolation partition mode according to the five-hole pressure value, and the interpolation partition mode is divided into an inner zone mode and an outer zone mode;

When the interpolation partition mode is the inner zone mode, the pressure values of the five holes are processed based on the inner zone interpolation file to obtain the airflow direction angle, total pressure and static pressure of the measuring point;

When the interpolation partition mode is the outer zone mode, the pressure values of the five holes are processed based on the outer zone interpolation file to obtain the airflow direction angle, total pressure and static pressure of the measuring point;

The flow velocity of the flow field is calculated based on the total pressure and static pressure of the flow field.

Further, the inner zone interpolation file includes the inner zone direction calibration coefficient curve, the inner zone total pressure coefficient calibration curve and the inner zone static pressure coefficient calibration curve; the outer zone interpolation file includes the outer zone direction calibration coefficient curve, the outer zone total pressure coefficient curve Pressure coefficient calibration curve and outer zone static pressure coefficient calibration curve.

Further, determining the interpolation partition mode according to the five-hole pressure value includes:

The interpolation partition mode is determined according to the number of the hole with the largest pressure value among the five hole pressure values: if the pressure value of the No. 2 hole probe is the largest, it is the inner zone mode, and the other holes are the outer zone mode when the probe pressure value is the largest.

Further, the pressure value of the five holes is processed based on the interpolation file in the inner region to obtain the airflow direction angle, total pressure and static pressure of the measuring point, including:

Calculate the yaw angle calibration coefficient and the pitch angle calibration coefficient according to the pressure value of the five holes;

Based on the yaw angle calibration coefficient and the pitch angle calibration coefficient, the inner zone direction calibration coefficient curve is inquired by the linear interpolation method, so as to obtain the yaw angle and the pitch angle;

Based on the yaw angle and pitch angle, the calibration curve of the total pressure coefficient in the inner area is inquired by the linear interpolation method, so as to obtain the total pressure calibration coefficient, and the total pressure of the flow field is calculated according to the pressure value of the five holes and the total pressure calibration coefficient;

Based on the yaw angle and pitch angle, the static pressure coefficient calibration curve of the inner region is queried by the linear interpolation method to obtain the static pressure calibration coefficient, and the static pressure of the flow field is calculated according to the five-hole pressure value and the static pressure calibration coefficient.

Further, the pressure value of the five holes is processed based on the outer area interpolation file, and the airflow direction angle, total pressure and static pressure of the measuring point are obtained, including:

Calculate the calibration coefficient of the circumference angle and the calibration coefficient of the cone angle according to the pressure value of the five holes;

Based on the circumference angle calibration coefficient and the cone angle calibration coefficient, the outer zone direction calibration coefficient curve is inquired through a linear interpolation method to obtain the circumference angle and the cone angle;

Based on the circumference angle and the cone angle, the total pressure coefficient calibration curve of the outer area is inquired by the linear interpolation method, so as to obtain the total pressure calibration coefficient, and the total pressure of the flow field is calculated according to the five-hole pressure value and the total pressure calibration coefficient;

Based on the circumference angle and the cone angle, the static pressure coefficient calibration curve of the outer area is queried by the linear interpolation method to obtain the static pressure calibration coefficient, and the static pressure of the flow field is calculated according to the five-hole pressure value and the static pressure calibration coefficient.

Compared with the prior art, the present invention has the following advantages:

1. The present invention adopts the interpolation file in the inner area to process the measuring points whose inflow angle is in the inner area, and uses the interpolation file in the outer area to measure the measuring points whose inflow angle is in the outer area. The incoming flow angle range is increased from ±30° to ±45°.

2. The present invention overcomes the problem of inaccurate measurement caused by the separation of the boundary layer of the air flow in some areas of the probe when the incoming flow angle is too large, and the pressure-sensing holes in the separation area will fail.

Based on the above reasons, the present invention can be widely promoted in the field of flow field measurement.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a flow chart of the method of partition interpolation according to the present invention.

FIG. 2 is a schematic diagram of an interpolation partition mode of the present invention.

FIG. 3 is a flow chart of the linear interpolation operation of the present invention.

FIG. 4 is a schematic diagram of the calibration coefficient curve of the inner region direction according to the present invention.

FIG. 5 is a schematic diagram of the calibration curve of the total pressure coefficient in the inner region of the present invention.

FIG. 6 is a schematic diagram of the calibration curve of the static pressure coefficient in the inner zone of the present invention.

FIG. 7 is a schematic diagram of the inflow angle of the inner zone of the present invention.

FIG. 8 is a schematic diagram of the angle of incoming flow from the outer zone of the present invention.

Detailed ways

In order to make those skilled in the art better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only Embodiments are part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "first", "second" and the like in the description and claims of the present invention and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used may be interchanged under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

As shown in FIG. 1 , the present invention provides a subarea interpolation method of a five-hole probe based on a flow field under a large incoming flow angle, including:

Get the inner and outer interpolation files. The inner region interpolation file includes the inner region direction calibration coefficient curve, the inner region total pressure coefficient calibration curve, and the inner region static pressure coefficient calibration curve. The inner area interpolation file has been calibrated by the manufacturer before the five-hole probe leaves the factory, as shown in Figure 4 to Figure 6. The outer zone interpolation file includes the outer zone direction calibration coefficient curve, the outer zone total pressure coefficient calibration curve and the outer zone static pressure coefficient calibration curve. The outer area interpolation file is calibrated by the user before use.

The five-hole pressure value collected by the five-hole probe is acquired, and the interpolation partition mode is determined according to the five-hole pressure value, and the interpolation partition mode is divided into an inner zone mode and an outer zone mode. Specifically, the interpolation partition mode is determined according to the number of the hole with the largest pressure value among the five hole pressure values: if the pressure value of the No. 2 hole probe is the largest, it is the inner zone mode, and the rest of the holes with the highest pressure value are the outer zone mode. The area division is shown in Figure 2. In the present invention, the outer zone modes include zone 1 mode with the highest probe pressure value in hole 1, zone 3 mode with the highest probe pressure value in hole 3, zone 4 mode with the highest probe pressure value in hole 4, and zone 4 mode with the highest probe pressure value in hole 4. The 5-zone mode with the maximum value of the hole probe pressure. And each outer zone mode includes independent outer zone calibration files, namely outer zone direction calibration coefficient curve, outer zone total pressure coefficient calibration curve and outer zone static pressure coefficient calibration curve.

Specifically, when the airflow angle of the incoming flow is small, each pressure-sensing hole on the probe is effective, and the pressure can be sensed correctly. Using the pressure data measured by the five pressure-sensing holes, the parameters of the measuring point can be interpolated. . However, when the airflow direction is greater than the probe angle (>25°), the airflow will be separated when passing through the probe head, so that some of the pressure-sensing holes are in the separation area and fail. At this time, the pressure-sensing hole facing the incoming flow direction (the pressure-sensing hole with the largest pressure value), the pressure-sensing hole on both sides of the hole, and the pressure data obtained from the No. 2 hole are selected to interpolate the parameters of the measuring point. . At this time, the five-hole needle becomes four four-hole needles. When the five-hole probe is in use, five pressure sensors are connected through a pressure measuring tube to obtain the pressure value of each hole.

When the incoming flow angle is small, the central pressure-sensing hole P2 has the maximum pressure. As the incoming flow angle increases, the boundary layer is separated in some areas of the probe, and when some pressure-sensing holes fail, the hole with the highest pressure value becomes a new central hole. According to the pressure values collected by the five pressure-sensing holes, the probe head is divided into five zones. The area corresponding to the P2 hole is defined as the inner area, and the areas corresponding to the other four pressure-sensing holes are arranged in numbers and are the outer area. Each outer zone occupies a 45° sector of space, as shown in Figure 2.

When the interpolation partition mode is the inner zone mode, the pressure values of the five holes are processed based on the inner zone interpolation file to obtain the airflow direction angle, total pressure and static pressure of the measuring point. As shown in FIG. 3 , it includes: calculating the yaw angle calibration coefficient and the pitch angle calibration coefficient according to the pressure value of the five holes; based on the yaw angle calibration coefficient and the pitch angle calibration coefficient, querying the inner zone direction calibration coefficient through a linear interpolation method curve to obtain the yaw and pitch angles, as shown in Figure 4, each point in the figure corresponds to a pair of known yaw and pitch angles, and the yaw and pitch angles of other non-known positions can be obtained through It is obtained by interpolating its relative position to the known yaw and pitch angles. Based on the yaw angle and pitch angle, the calibration curve of the total pressure coefficient in the inner area is queried by the linear interpolation method, so as to obtain the total pressure calibration coefficient. The total pressure of Calculate the static pressure of the flow field.

Specifically, in the inner region mode, the inner region interpolation file defines the following parameters:

为孔1、孔3、孔4、孔5压力平均值。探针头部的五个感压孔会分别采集到不同的压力。利用这五个压力值，通过公式(1)-(5)可以计算出对应来流角度下的K_α和K_β，在通过线性插值方式，查询内区方向校准系数曲线，从而可以确定偏航角α与俯仰角β。具体地如图4所示，在方向校准曲线中找到点(K_α，K_β)的位置，计算出点(K_α，K_β)与其所在的最小四边形各边之间的距离，用线性插值法插值得到偏航角α与俯仰角β。Among them, K _α is the α direction calibration coefficient, K _β is the β direction calibration coefficient, α and β are the yaw angle and pitch angle respectively, C _Pt is the total pressure calibration coefficient, C _Ps is the static pressure calibration coefficient, P ₁ -P ₅ is the pressure value of holes 1-5, P _t is the total pressure, P _s is the static pressure,

It is the average pressure of hole 1, hole 3, hole 4 and hole 5. The five pressure-sensing holes on the probe head will collect different pressures respectively. Using these five pressure values, K _α and K _β at the corresponding inflow angle can be calculated by formulas (1)-(5), and the yaw can be determined by querying the calibration coefficient curve in the direction of the inner area by means of linear interpolation. angle α and pitch angle β. Specifically, as shown in Figure 4, find the position of the point (K _α , K _β ) in the direction calibration curve, calculate the distance between the point (K _α , K _β ) and each side of the smallest quadrilateral where it is located, and use linear interpolation The yaw angle α and the pitch angle β are obtained by normal interpolation.

According to the yaw angle α and the pitch angle β, the calibration curve of the total pressure coefficient in the inner area and the calibration curve of the static pressure coefficient in the inner area are inquired by linear interpolation, so as to obtain the total pressure calibration coefficient C _Pt and the static pressure calibration coefficient C _Ps . Then, according to formulas (3) and (4), the total pressure P _t and static pressure P _s of the process can be obtained by inversion.

When the interpolation partition mode is the outer zone mode, the pressure values of the five holes are processed based on the outer zone interpolation file to obtain the total pressure and static pressure of the flow field. The method includes: calculating the calibration coefficient of the circumference angle and the calibration coefficient of the cone angle according to the pressure value of the five holes; based on the calibration coefficient of the circumference angle and the calibration coefficient of the cone angle, querying the calibration coefficient curve of the direction of the outer area through the linear interpolation method, so as to obtain the circumference angle and the cone angle Based on the circumference angle and the cone angle, the total pressure coefficient calibration curve of the outer area is queried by the linear interpolation method, so as to obtain the total pressure calibration coefficient, and the total pressure of the flow field is calculated according to the five-hole pressure value and the total pressure calibration coefficient; based on The circumference angle and the cone angle are obtained by querying the static pressure coefficient calibration curve of the outer area through a linear interpolation method to obtain the static pressure calibration coefficient, and the static pressure of the flow field is calculated according to the five-hole pressure value and the static pressure calibration coefficient.

Specifically, when the probe measures the incoming flow in a general direction, the air flow will be separated when passing through the probe head, so that part of the pressure-sensing hole is in the separation area and fails. At this time, select the pressure-sensitive hole facing the incoming flow direction (the pressure-sensitive hole with the largest pressure value), the pressure-sensitive hole on both sides of the hole, and the pressure data obtained from the No. 2 hole to calculate the taper angle and the circumference angle coefficient And the total pressure and static pressure coefficient, that is, the five-hole needle is equivalent to the four-hole needle at this time.

在确定所要校准的布点，再换算得到对应的偏航角α和俯仰角β。校准的探针转角范围为α≤45°，β≤45°。小来流角度下，不同校准点间的偏航角α和俯仰角β相距5°；大来流角度下，不同校准点间的圆周角θ和锥角

相距5°。标定后的总压系数校准曲线示意图和静压系数校准曲线示意图形式与图5-图6中的曲线类似，此处不再赘述。In the outer zone mode, it corresponds to zone 1 mode with the highest probe pressure value in hole 1, zone 3 mode with the highest probe pressure value in hole 3, zone 4 mode with the highest probe pressure value in hole 4, and zone 4 mode with probe pressure value in hole 5. 5-zone mode with maximum pressure value. The calibration coefficient curve of the outer zone direction, the calibration curve of the total pressure coefficient of the outer zone and the calibration curve of the static pressure coefficient of the outer zone in each mode are pre-calibrated respectively. When calibrating, for the small inflow angle area, first fix an α angle, then rotate the β angle, and scan and calibrate one by one until the entire inner area is swept; for the large inflow angle area, first pass the circumference angle θ and cone angle.

After determining the points to be calibrated, the corresponding yaw angle α and pitch angle β are obtained by conversion. The calibrated probe rotation angle range is α≤45°, β≤45°. Under small incoming flow angle, the yaw angle α and pitch angle β between different calibration points are 5° apart; under large incoming flow angle, the circumference angle θ and cone angle between different calibration points

5° apart. The schematic diagram of the calibration curve of the total pressure coefficient and the schematic diagram of the calibration curve of the static pressure coefficient after calibration are similar to the curves in Figs.

At a small incoming flow angle (inner zone), the incoming flow angle is defined using the yaw angle α and the pitch angle β. Facing the direction of oncoming flow, the right yaw is positive. Under the large incoming flow angle (outer area), the incoming flow angle is defined by the circumferential angle θ and the cone angle φ, where φ is always positive and is the angle between the airflow direction and the probe head, and θ is defined as the incoming flow from the measuring point The angle between the projection of the angle in the XY plane and the X axis, the counterclockwise direction is positive. Figure 7 shows a schematic diagram of the yaw angle α and pitch angle β in the inner zone mode, and Figure 8 shows the definitions of the circumference angle θ and the cone angle φ in the outer zone mode. The conversion relationship between each angle is:

Further, in the outer zone mode, the outer zone interpolation file defines the following parameters:

为第i区方向系数，C_Pti,C_Psi为第i区总压系数和静压系数。In the above formula, i represents the number of the hole with the largest force, and the corresponding formula represents the calculation method of each coefficient of the five-hole probe under the middle working condition. K _θi ,

is the direction coefficient of the i-th zone, C _Pti , C _Psi are the total pressure coefficient and the static pressure coefficient of the i-th zone.

再通过线性插值方式，查询对应的第i外区方向校准系数曲线，从而可以确定圆周角θ和锥角φ。在第i外区方向校准曲线中找到点

的位置，用线性插值法插值得到圆周角θ和锥角φ。再根据圆周角θ和锥角φ通过线性插值方式查询第i外区总压系数校准曲线和第i外区静压系数校准曲线，从而获取总压校准系数C_Pti和静压校准系数C_Psi。再根据第i区的公式反推求出流程的总压P_t和静压P_s。By K _θi under specific conditions, and

Then through the linear interpolation method, query the corresponding ith outer zone direction calibration coefficient curve, so that the circumference angle θ and the cone angle φ can be determined. Find the point in the ith outer zone orientation calibration curve

The position of , use linear interpolation to obtain the circumference angle θ and cone angle φ. Then according to the circumference angle θ and cone angle φ, the total pressure coefficient calibration curve of the i-th outer zone and the static pressure coefficient calibration curve of the i-th outer zone are inquired by linear interpolation, so as to obtain the total pressure calibration coefficient C _Pti and the static pressure calibration coefficient C _Psi . The total pressure P _t and static pressure P _s of the process can be obtained by inversion according to the formula in the i-th zone.

The flow velocity of the flow field is calculated based on the total pressure and static pressure of the flow field. Including the back-calculation of the flow field velocity by the following formula:

P _t -P _s =(1/2)ρv ²

where ρ is the air density and v is the velocity of the flow field.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (5)

1. A partition interpolation method of a five-hole probe under a large incoming flow angle is characterized by comprising the following steps:

acquiring an inner region interpolation file and an outer region interpolation file;

acquiring a five-hole pressure value acquired by a five-hole probe, and determining an interpolation partition mode according to the five-hole pressure value, wherein the interpolation partition mode is divided into an inner partition mode and an outer partition mode;

when the interpolation partition mode is an inner region mode, processing the five-hole pressure value based on the inner region interpolation file to obtain an airflow direction angle, a total pressure and a static pressure of a measuring point, wherein the inner region interpolation file defines the following parameters:

wherein, K_αIs a calibration coefficient of alpha direction, K_βIs a beta direction calibration coefficient, alpha and beta are yaw angle and pitch angle, respectively, C_PtFor total pressure calibration factor, C_PsFor static pressure calibration factor, P₁-P₅At a pressure of 1-5 holes, P_tIs the total pressure, P_sIn order to be at a static pressure,

the average values of the pressures of the holes 1, 3, 4 and 5 are shown;

when the interpolation partition mode is an outer area mode, processing the five-hole pressure value based on the outer area interpolation file to obtain an airflow direction angle, total pressure and static pressure of a measuring point, wherein the outer area interpolation file defines the following parameters:

in the above formula, i represents the number of the hole with the largest stress, the corresponding formula represents the calculation method of each coefficient of the five-hole probe under the working condition, and K_θi,

Is the i-th zone directional coefficient, C_Pti,C_PsiThe total pressure coefficient and the static pressure coefficient of the ith area are shown;

and calculating the flow velocity of the flow field based on the total pressure and the static pressure of the airflow at the measuring point.

2. The zonal interpolation method of a five-hole probe at a high inflow angle of claim 1, wherein the inner zone interpolation file comprises an inner zone direction calibration coefficient curve, an inner zone total pressure coefficient calibration curve, and an inner zone static pressure coefficient calibration curve; the outer area interpolation file comprises an outer area direction calibration coefficient curve, an outer area total pressure coefficient calibration curve and an outer area static pressure coefficient calibration curve.

3. The partition interpolation method for the five-hole probe under the large incoming flow angle according to claim 1 or 2, wherein the determining of the interpolation partition mode according to the five-hole pressure value comprises:

determining an interpolation partition mode according to the serial number of the hole with the maximum pressure value in the five-hole pressure values: if be the district mode when No. 2 hole probe pressure values are the biggest, the district mode is outer to the biggest to the probe pressure value in the remaining hole.

4. The method for performing zone interpolation on a five-hole probe under a large incoming flow angle according to claim 3, wherein the step of processing the five-hole pressure value based on the inner zone interpolation file to obtain the airflow direction angle, the total pressure and the static pressure of the measuring point comprises the following steps:

calculating a yaw angle calibration coefficient and a pitch angle calibration coefficient according to the five-hole pressure value;

inquiring an inner area direction calibration coefficient curve by a linear interpolation method based on the yaw angle calibration coefficient and the pitch angle calibration coefficient so as to obtain a yaw angle and a pitch angle;

inquiring an inner area total pressure coefficient calibration curve by a linear interpolation method based on the yaw angle and the pitch angle so as to obtain a total pressure calibration coefficient, and calculating the total pressure of the flow field according to the five-hole pressure value and the total pressure calibration coefficient;

and inquiring an inner region static pressure coefficient calibration curve through a linear interpolation method based on the yaw angle and the pitch angle so as to obtain a static pressure calibration coefficient, and calculating the static pressure of the flow field according to the five-hole pressure value and the static pressure calibration coefficient.

5. The zonal interpolation method of the five-hole probe under the incoming flow angle of claim 3, wherein the processing of the five-hole pressure value based on the outer zone interpolation file to obtain the airflow direction angle, total pressure and static pressure of the measurement point comprises:

calculating a circumferential angle calibration coefficient and a cone angle calibration coefficient according to the five-hole pressure value;

inquiring an outer region direction calibration coefficient curve by a linear interpolation method based on the circumferential angle calibration coefficient and the cone angle calibration coefficient so as to obtain a circumferential angle and a cone angle;

inquiring an outer region total pressure coefficient calibration curve by a linear interpolation method based on the circumferential angle and the cone angle so as to obtain a total pressure calibration coefficient, and calculating the total pressure of the flow field according to the five-hole pressure value and the total pressure calibration coefficient;

and inquiring an outer zone static pressure coefficient calibration curve by a linear interpolation method based on the circumferential angle and the cone angle so as to obtain a static pressure calibration coefficient, and calculating the static pressure of the flow field according to the five-hole pressure value and the static pressure calibration coefficient.

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