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).

scholarly journals Techniques for the Determination of Local Dynamic Pressure and Angle of Attack on a Horizontal Axis Wind Turbine

10.2172/61151 ◽  
1995 ◽  
Author(s):  
Derek E. Shipley ◽  
Mark S. Miller ◽  
Michael C. Robinson ◽  
Marvin W. Luttges ◽  
David A. Simms
Keyword(s):  
Wind Turbine ◽  
Dynamic Pressure ◽  
Angle Of Attack ◽  
Horizontal Axis ◽  
Local Dynamic ◽  
Horizontal Axis Wind Turbine

scholarly journals Bioinspired wind field estimation—part 1: Angle of attack measurements through surface pressure distribution

2018 ◽  
Vol 10 (3) ◽  
pp. 273-284 ◽  
Author(s):  
Nikola Gavrilovic ◽  
Murat Bronz ◽  
Jean-Marc Moschetta ◽  
Emmanuel Benard
Keyword(s):  
Angle Of Attack ◽  
Time Estimation ◽  
Pressure Measurements ◽  
Surface Pressure Distribution ◽  
Additional Equipment ◽  
Field Estimation ◽  
Aerial Vehicle ◽  
Unsteady Interaction ◽  
Wind Vane ◽  
Local Angle

One of the major challenges of Mini-Unmanned Aerial Vehicle flight is the unsteady interaction with turbulent environment while flying in lower levels of atmospheric boundary layer. Following inspiration from nature we expose a new system for angle of attack estimation based on pressure measurements on the wing. Such an equipment can be used for real-time estimation of the angle of attack during flight or even further building of wind velocity vector with additional equipment. Those information can find purpose in control and stabilization of the aircraft due to inequalities seen by the wing or even for various soaring strategies that rely on active control for energy extraction. In that purpose, flying wing aircraft has been used with totally four span-wise locations for local angle of attack estimation. In-flight angle of attack estimation from differential pressure measurements on the wing has been compared with magnetic sensor with wind vane. The results have shown that pressure ports give more reliable estimation of angle of attack when compared to values given by wind vane attached to a specially designed air-boom. Difference in local angle of attack at four span-wise locations has confirmed spatial variation of turbulence in low altitude flight. Moreover, theoretical law of energy dissipation for wind components described by Kaimal spectrum has shown acceptable match with estimated ones.

On the Possibilities of Improving the Accuracy of the Evaluation of Inertia Forces in Laminar and Turbulent Films

1974 ◽  
Vol 96 (1) ◽  
pp. 69-77 ◽  
Author(s):  
V. N. Constantinescu ◽  
S. Galetuse
Keyword(s):  
Turbulent Flow ◽  
Total Pressure ◽  
Static Pressure ◽  
Reverse Flow ◽  
Dynamic Pressure ◽  
Fluid Films ◽  
Approximate Integral ◽  
Laminar And Turbulent Flow ◽  
Improved Accuracy ◽  
Inertia Forces

The momentum equations for laminar and turbulent flow in fluid films are evaluated by assuming that the shape of the velocity profiles is not strongly affected by the presence of the inertia forces. Approximate integral momentum equations are thus obtained, which are similar in form to those proposed in a previous paper, but have an improved accuracy in evaluating the influence of the inertia forces, especially when the film exhibits regions with reverse flow. It is thus found that the overall influence of the inertia forces consists, for example, in a partial conversion of the static pressure into dynamic pressure when the flow is accelerated, rather than a complete conservation of the total pressure as assumed in a previous work.

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 Analisis Airfoil Double-Slot Flap LS(01)-0417 MOD Dengan Airfoil Tanpa Flap Nasa SC(2) 0610

2018 ◽  
Vol 11 (2) ◽  
pp. 49
Author(s):  
Gaguk Jatisukamto ◽  
Mirna Sari
Keyword(s):  
Computational Fluid Dynamic ◽  
Static Pressure ◽  
Fluid Dynamic ◽  
Dynamic Pressure ◽  
Lift Coefficient ◽  
Pressure Coefficient ◽  
Angle Of Attack ◽  
Airflow Velocity ◽  
The Difference ◽  
The Stability

Kestabilan pesawat terbang ditentukan oleh desain airfoil sayap dan ekor. Perbedaan kecepatan aliran udara antara permukaan atas dan bawah airfoil menghasilkan perbedaan tekanan sehingga akan memberikan gaya angkat (lift) pada sayap. Perbedaan tekanan udara pada permukaan sayap dinyatakan dengan pressure coefficient (Cp), yaitu perbedaan tekanan statik lokal dengan tekanan statik aliran bebas. Koefisien lift (Cl) adalah rasio antara gaya angkat (lift) dengan tekanan dinamis. Peningkatan angka CL sebesar 20,4% pada riset sebelumnya diperoleh berdasarkan simulasi penambahan flap. Tujuan penelitian ini adalah membandingkan hasil simulasi airfoil double slot flap LS(01)-0417 MOD  dengan airfoil NASA SC(2) 0610 yang tanpa flap dan mencari korelasi antara sudut serang (?) dengan koefisien lift (Cl ).Metodologi penelitian dilakukan dengan simulasi Computational Fluid Dynamic (CFD). Hasil penelitian dapat disimpulkan bahwa koefisien lift CL untuk airfoil double slot flap LS(01)-0417 MOD menghasilkan CL = 1,498 sedangkan dengan sudut serang ? = 16o sedangkan airfoil NASA SC(2) 0610 tanpa flap memiliki nilai CL = 1,095 dengan sudut serang 13o. The stability of the aircraft is ordered by the airfoil design of the wings and the tail. The difference in flow velocity between the surface and the bottom of the airfoil will produce styles that will present lift  on the wings. The difference in airflow velocity between the top and bottom surfaces of the airfoil produces a pressure difference so it will provide lift (lift) on the wing. The lift coefficient (CL) is the ratio between lift with dynamic pressure. The difference of air pressure on the wing surface is expressed by pressure coefficient (Cp), the difference of local static pressure with free flow static pressure. The lift coefficient (Cl) is the ratio of lift to dynamic pressure. An increase in CL value of 20.4% in previous research was obtained based on the simulation of flap addition. The purpose of this research is comparison between airfoil double slot flap LS (01)-0417 MOD with airfoil NASA SC (2) 0610 without flap and search between angle of attack (?) with coefficient of lift (Cl). Method research is done by Computational Fluid Dynamic (CFD). The result of this research can be concluded that lift coefficient CL for double slot airfoil flap LS (01)-0417 MOD yield CL = 1,498 while with angle of attack ? = 16o while airfoil NASA SC (2) 0610 without flap have value CL = 1,095 with angle of attack 13o

Experimental and Numerical Characterization of Transonic Compressor Subjected to Inlet Distortion

2018 ◽  
Author(s):  
Mark H. Ross ◽  
Andrew Oliva ◽  
Vicente Jerez Fidalgo ◽  
Ryan T. Kelly ◽  
Aleksandar Jemcov ◽  
...  
Keyword(s):  
Total Pressure ◽  
Static Pressure ◽  
Axial Compressor ◽  
Sampling Frequency ◽  
Pressure Measurements ◽  
Transonic Compressor ◽  
Inlet Distortion ◽  
High Sampling ◽  
Blade Row ◽  
Initial Work

In this work we show preliminary results of an experimental and numerical investigation of a transonic axial compressor subjected to a 90 degree circumferential inlet total pressure distortion. The fundamental goal of the investigation is to establish an experimental dataset to be used in the validation of numerical simulation tools. The special interest of this investigation is the ability of the advanced blade row tools such as harmonic balance to reproduce the experimental results. Therefore, this report is account of the initial work of the ongoing project of the validation of advanced blade row tools in ANSYS CFX. Measurements of the compressor’s performance and efficiency were obtained by “traversing” the distortion around the test article inlet over 24 separate experiments. The resultant 2-D total pressure and total temperature contours at three measurement stations are shown. The experimental instrumentation package also included high sampling frequency rotor casing static pressure measurements and high sampling frequency rotor exit total pressure measurements. Phase locked averaged casing static pressure and rotor exit total pressure at four locations relative to the inlet distortion are shown. The initial set of computations presented in this paper concentrate on a full annulus transient simulation conducted in preparation for the harmonic analysis simulations.

Numerical investigations on the effect of volute casing treatment for performance augmentation in a centrifugal fan

2021 ◽  
pp. 095440622110341
Author(s):  
Manjunath L Nilugal ◽  
K Vasudeva Karanth ◽  
Madhwesh N
Keyword(s):  
Total Pressure ◽  
Static Pressure ◽  
Numerical Study ◽  
Pressure Coefficient ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Centrifugal Fan ◽  
Casing Treatment ◽  
Sliding Mesh ◽  
Optimum Configuration

This article presents the effect of volute chamfering on the performance of a forward swept centrifugal fan. The numerical analysis is performed to obtain the performance parameters such as static pressure rise coefficient and total pressure coefficient for various flow coefficients. The chamfer ratio for the volute is optimized parametrically by providing a chamfer on either side of the volute. The influence of the chamfer ratio on the three dimensional flow domain was investigated numerically. The simulation is carried out using Re-Normalisation Group (RNG) k-[Formula: see text] turbulence model. The transient simulation of the fan system is done using standard sliding mesh method available in Fluent. It is found from the analysis that, configuration with chamfer ratio of 4.4 is found be the optimum configuration in terms of better performance characteristics. On an average, this optimum configuration provides improvement of about 6.3% in static pressure rise coefficient when compared to the base model. This optimized chamfer configuration also gives a higher total pressure coefficient of about 3% validating the augmentation in static pressure rise coefficient with respect to the base model. Hence, this numerical study establishes the effectiveness of optimally providing volute chamfer on the overall performance improvement of forward bladed centrifugal fan.

scholarly journals Reproducibility of C. I. P.-compatible dynamic pressure measurements

2020 ◽  
Vol 87 (10) ◽  
pp. 630-636
Author(s):  
Oliver Slanina ◽  
Susanne Quabis ◽  
Robert Wynands
Keyword(s):  
Dynamic Pressure ◽  
Storage Conditions ◽  
Dynamic Measurement ◽  
Gas Pressure ◽  
Pressure Measurements ◽  
Small Arms ◽  
Minimum Pressure ◽  
Maximum Value ◽  
Preliminary Study ◽  
Dynamic Pressure Measurements

AbstractTo ensure the safety of users like hunters and sports shooters, the dynamic pressure inside an ammunition cartridge must not exceed a maximum value. We have investigated the reproducibility of the dynamic measurement of the gas pressure inside civilian ammunition cartridges during firing, when following the rules formulated by the Permanent International Commission for the Proof of Small Arms (C. I. P.). We find an in-house spread of 0.8 % between maximum and minimum pressure for runs with the same barrel and of 1.8 % among a set of three barrels. This sets a baseline for the expected agreement in measurement comparisons between different laboratories. Furthermore, a difference of more than 3 % is found in a preliminary study of the influence of ammunition storage conditions.

Total Pressure Measurements for Chloroform + Acetone + Toluene at 303.15 K

1994 ◽  
Vol 39 (3) ◽  
pp. 488-492 ◽  
Author(s):  
Jay A. Hopkins ◽  
Venkat R. Bhethanabotla ◽  
Scott W. Campbell
Keyword(s):  
Total Pressure ◽  
Pressure Measurements
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