scholarly journals Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements

2012 ◽  
Vol 5 (11) ◽  
pp. 2569-2579 ◽  
Author(s):  
A. R. Rodi ◽  
D. C. Leon
Keyword(s):  
Pressure Measurement ◽  
Static Pressure ◽  
Dynamic Pressure ◽  
Differential Pressure ◽  
Limiting Factors ◽  
Measurement Unit ◽  
Sensitivity Factor ◽  
Pressure Measurements ◽  
Wide Range ◽  
Research Aircraft

Abstract. A method is described that estimates the error in the static pressure measurement on an aircraft from differential pressure measurements on the hemispherical surface of a Rosemount model 858AJ air velocity probe mounted on a boom ahead of the aircraft. The theoretical predictions for how the pressure should vary over the surface of the hemisphere, involving an unknown sensitivity parameter, leads to a set of equations that can be solved for the unknowns – angle of attack, angle of sideslip, dynamic pressure and the error in static pressure – if the sensitivity factor can be determined. The sensitivity factor was determined on the University of Wyoming King Air research aircraft by comparisons with the error measured with a carefully designed sonde towed on connecting tubing behind the aircraft – a trailing cone – and the result was shown to have a precision of about ±10 Pa over a wide range of conditions, including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, geometric altitude data from a combined Global Navigation Satellite System (GNSS) and inertial measurement unit (IMU) system are used to estimate acceleration effects on the error, and the algorithm is shown to predict corrections to a precision of better than ±20 Pa under those conditions. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are discussed.

scholarly journals Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements

2012 ◽  
Vol 5 (3) ◽  
pp. 3611-3643 ◽  
Author(s):  
A. R. Rodi ◽  
D. C. Leon
Keyword(s):  
Pressure Measurement ◽  
Static Pressure ◽  
Satellite System ◽  
Differential Pressure ◽  
Limiting Factors ◽  
Measurement Unit ◽  
Pressure Measurements ◽  
Factors Affecting ◽  
Wide Range ◽  
Research Aircraft

Abstract. Geometric altitude data from a combined Global Navigation Satellite System (GNSS) and inertial measurement unit (IMU) system on the University of Wyoming King Air research aircraft are used to estimate acceleration effects on static pressure measurement. Using data collected during periods of accelerated flight, comparison of measured pressure with that derived from GNSS/IMU geometric altitude show that errors exceeding 150 Pa can occur which is significant in airspeed and atmospheric air motion determination. A method is developed to predict static pressure errors from analysis of differential pressure measurements from a Rosemount model 858 differential pressure air velocity probe. The method was evaluated with a carefully designed probe towed on connecting tubing behind the aircraft – a "trailing cone" – in steady flight, and shown to have a precision of about ±10 Pa over a wide range of conditions including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, compared to the GNSS/IMU data, this algorithm predicts corrections to a precision of better than ±20 Pa. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are examined.

Pressure Measurements Around a Rotating Cylinder With and Without Crossflow

1993 ◽  
Vol 115 (3) ◽  
pp. 526-528 ◽  
Author(s):  
A. A. Tawfek ◽  
B. V. S. S. S. Prasad ◽  
A. K. Mohanty
Keyword(s):  
Pressure Transducer ◽  
Static Pressure ◽  
Rotating Cylinder ◽  
Differential Pressure ◽  
Pressure Measurements ◽  
Orthogonal Axis ◽  
Differential Pressure Transducer ◽  
Slip Ring

Static pressure measurements around a cylinder rotating about an orthogonal axis with and without superimposed crossflow are carried out by using a capacitance type differential pressure transducer in conjunction with a slip-ring apparatus. A coefficient of pressure (Cp) is defined for the rotating cylinder and typical variations of Cp along its length and periphery are presented.

A High Resolution, Hot-Wire Micro-Flow Meter with Various Applications

1992 ◽  
Vol 11 (3) ◽  
pp. 93-99
Author(s):  
H. Bardeau ◽  
A. Druilhet
Keyword(s):  
High Resolution ◽  
Pressure Difference ◽  
Dynamic Pressure ◽  
Differential Pressure ◽  
Pressure Measurements ◽  
Hot Wire ◽  
Flow Meter ◽  
Turbulence Measurements ◽  
Micro Flow

We have perfected a very sensitive, high-resolution electronic flow-meter. The module we have been working on has a cut-off frequency of 200 Hz. It works in a range of pressure-difference from 1 to 100 pascals, with a resolution of 0.1 pascal. The device has enabled us to carry out a series of ground measurements tests of the air's dynamic pressure and of the structure ratio of this parameter, as well as differential pressure measurements. Used as a very sensitive variometer, it has permitted measurements in altitude by means of a meteorological plane specially equipped for turbulence measurements. It can also be operational in a captive balloon or in a glider.

The influence of hole dimensions on static pressure measurements

1960 ◽  
Vol 7 (4) ◽  
pp. 550-564 ◽  
Author(s):  
R. Shaw
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Pressure Measurement ◽  
Friction Velocity ◽  
Static Pressure ◽  
Hole Diameter ◽  
Hole Size ◽  
Pressure Measurements ◽  
Size And Shape ◽  
Hole Dimensions

The pressure measured at a static pressure hole differs slightly from the true static pressure, by an amount which depends on the hole size and shape. The present investigation extends the range of previous work to determine the error in static pressure measurement in incompressible turbulent flow. The observed static pressure was always greater than the true static pressure. The results are presented in dimesionless form as a function of the Reynolds number based on hole diameter and friction velocity.

scholarly journals Aerodynamics Analysis of a Slotted A4412 Wind Turbine Airfoil Using CFD / Case Two

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Omar M. Elmosrati
Keyword(s):  
Static Pressure ◽  
Dynamic Pressure ◽  
Ansys Fluent ◽  
Wind Speeds ◽  
Velocity Magnitude ◽  
Commercial Code ◽  
Wide Range ◽  
Wind Velocities ◽  
Wind Turbine Airfoil ◽  
Inlet Boundary Condition

The static pressure, dynamic pressure and velocity magnitude are important parameters and have a strong influence on airfoil lift force. In this paper a slotted NACA4412 airfoil profile is considered for analysis by using the commercial code ANSYS-FLUENT 14.5® at an inlet boundary condition of different approaching wind velocities for various airfoil angles of attack in the range 0?to 24?. Renormalized group (RNG) k-? turbulence model with enhanced wall function is used for the analysis due its’ wide usage in the aerodynamic industry. Variations of the physical properties like static pressure, dynamic pressure and velocity magnitude are plotted in form of contours and/or vectors. The main aim of the research is to find out a method to enhance the efficiency of the selected airfoil and its’ workability in a wide range of low and high wind speeds which might make it suitable for installation and operation in different climates.This feasibility of enhancing the lift is and/or minimizing the drag is done by CFD on a series of independently modified NACA4412 airfoils. The current one is called Case 2. The analysis output of Case 2 is not encouraging. It does not show any improvement in NACA4412 airfoil efficiency and therefore it is classified as (obsolete).

Aircraft Sensor Quality in SESAME 1979: Results of Tower Fly-Bys and Aircraft Intercomparison

1981 ◽  
Vol 62 (3) ◽  
pp. 403-411
Author(s):  
Diane E. Ziegler ◽  
John McCarthy
Keyword(s):  
Data Quality ◽  
South Dakota ◽  
Static Pressure ◽  
Pressure Measurements ◽  
Quality Of Data ◽  
Data Quality Assessment ◽  
Potential Sources ◽  
Research Aircraft ◽  
Aircraft Data

Instrumented research aircraft data quality during Project SESAME ‘79 is examined in a series of tower fly-bys designed to compare temperature and static pressure measurements with reference values obtained from sensors located on the towers. Aircraft studied included an NCAR Queen Air and Sabreliner, and the South Dakota T-28. Measurements indicate that the quality of data was within acceptable limits. A discussion of data quality assessment philosophy is given, along with specific means of identifying real and potential sources of error.

Horizontal tail local angle-of-attack and total pressure measurements through static pressure ports and Kiel pitot

2019 ◽  
Vol 123 (1268) ◽  
pp. 1476-1491
Author(s):  
R. M. Granzoto ◽  
L. A. Algodoal ◽  
G. J. Zambrano ◽  
G. G. Becker
Keyword(s):  
Total Pressure ◽  
Static Pressure ◽  
Dynamic Pressure ◽  
Angle Of Attack ◽  
Flight Test ◽  
Vertical Position ◽  
Local Dynamic ◽  
Pressure Measurements ◽  
Turbofan Engines ◽  
Local Angle

ABSTRACTAircraft handling qualities may be influenced by wing-tip flow separations and horizontal tail (HT) reduced efficiency caused by loss of local dynamic pressure or local tailplane flow separations in high angle-of-attack manoeuvres. From the flight tester’s perspective, provided that the test aircraft presents sufficient longitudinal control authority to overcome an uncommanded nose-up motion, this characteristic should not be a safety factor. Monitoring and measuring the local airflow in the aircraft’s HT provides information for safe flight-test envelope expansion and data for early aerodynamic knowledge and model validation. This work presents the development, installation and pre-flight calibration using computational fluid dynamics (CFD), flight-test calibration, results and benefits of differential pressure based local angle-of-attack and total pressure measurements through 20 static pressure ports and a Kiel pitot. These sensors were installed in a single-aisle, four-abreast, full fly-by-wire medium-range jet airliner with twin turbofan engines and conventional HT (low vertical position).

Barometry

2001 ◽  
Author(s):  
Fred V. Brock ◽  
Scott J. Richardson
Keyword(s):  
Sea Level ◽  
Atmospheric Pressure ◽  
Static Pressure ◽  
Unit Area ◽  
Dynamic Pressure ◽  
Pressure Gauge ◽  
Differential Pressure ◽  
Absolute Pressure ◽  
Gauge Pressure ◽  
Air Motion

The objective of barometry is to measure the static pressure exerted by the atmosphere. Static pressure is the force per unit area that would be exerted against any surface in the absence of air motion. It is an isotropic, scalar quantity. Dynamic pressure is the force per unit area due to air motion. It is a vector quantity, following the wind vector. This chapter is concerned with determining the static air pressure and doing so in the presence of air motion (wind) that requires special measurement techniques. The Earth’s atmosphere exerts a pressure on the surface of the Earth equal to the weight of a vertical column of air of unit cross-section. Since air is a fluid, this pressure, or force, is exerted equally in all directions. The static pressure at the surface is given by where g(z) = acceleration due to gravity at height z above sea level in ms-2, and ρ = density as a function of height, kg-3. The SI unit of pressure is the pascal, abbreviated as Pa. In meteorology, the preferred unit of pressure is the mb or the hPa (equivalent magnitude). Table 2-1 lists some conversion factors for units currently in use in pressure measurement and also for some units no longer favored. Standard sea level pressure in various units is shown in table 2-2. The last line of table 2-2 refers to the units of Ibf in-2,also called psi (pounds per square inch). Pressure measurements are often called absolute (psia), gauge (psig), or differential (psid). Absolute pressure is simply the total static pressure exerted by the gas (or fluid) and so the barometric pressure is also the absolute pressure. Gauge pressure is the pressure relative to ambient atmospheric pressure. Pressure in an automobile tire is measured relative to atmospheric pressure so it is gauge pressure, not absolute pressure. Differential pressure is the pressure relative to some other pressure. Gauge pressure is a special case of differential pressure. In addition to the static pressure there is a dynamic pressure exerted by wind flow.

Experiment of Driving Oil by Low Frequency Hydraulic Pulse of Low Permeability Reservoirs

2014 ◽  
Vol 675-677 ◽  
pp. 1490-1494
Author(s):  
Zeng Li Xiao ◽  
Jun Bin Chen ◽  
Wen Long Qin
Keyword(s):  
Static Pressure ◽  
Dynamic Pressure ◽  
Low Frequency ◽  
Low Permeability ◽  
Type I ◽  
Displacement Effect ◽  
Wide Range ◽  
Core Permeability ◽  
Low Permeability Reservoirs ◽  
Hydraulic Pulse

The fine grain, poor sorting and high cement content in low permeability reservoirs lead to poor reservoir property, low porosity and permeability and have strong damage to the reservoir .The conventional way of low permeability oil mining is mainly fracture and chemical flooding, which cost is relatively high and will cause serious irreparable damage to formation. People are in favor of physical oil production technology because it is no harm and pollution to the reservoir, more flexible to operate and it has wide range of application and low cost. By using high frequency pulse pressure servo system and ZC-type I, this paper examines the low-frequency vibration oil recovery indoor simulation test device hydraulic pulse oil displacement effect of low permeability cores. The experiment selecting the artificial core (permeability are less than 50), examines the effects of different hydraulic pulse parameters (frequency, static pressure and dynamic pressure) on low permeability core permeability and recovery factor. The results showed that only when the three parameter ,hydraulic pulse frequency, static pressure and dynamic pressure, suitably combined will greatly increase the reservoir recovery efficiency and reduce residual oil saturation.

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