scholarly journals The Evolution of Design: SALTS New Sail Training Schooner Project

2013 ◽  
Author(s):  
Stephen Duff ◽  
Fabio Fossati ◽  
Andy Claughton ◽  
Will Krzymowski ◽  
Tony Anderson
Keyword(s):  
Wind Tunnel ◽  
Parametric Study ◽  
Parametric Design ◽  
Experimental Investigations ◽  
Support Design ◽  
Hull Form ◽  
Towing Tank ◽  
Preliminary Results ◽  
International Team ◽  
Graphical Algorithm

The Sail and Life Training Society is building a new purpose-designed 35m wooden sail-training schooner for unrestricted foreign-going operations. Working with an international team of consultants, SALTS has initiated an ambitious agenda of analytical and experimental investigations to support design, including a parametric study of hull form as it relates to stability at high angles of heel, the development of bespoke parametric design and analysis tools using the graphical algorithm editor Grasshopper, a towing tank campaign at the Wolfson Unit to investigate the behavior of three keel profiles, and a wind tunnel campaign at Politecnico di Milano to investigate the behavior of fifteen sail plans. Preliminary results from these studies will be presented, set in the context of the unfolding story of the evolution of the design of the new vessel.

Experimental investigations of flow over NACA airfoils 0021 and 4412 of wind turbine blades with and without Tubercles

2021 ◽  
pp. 0309524X2110071
Author(s):  
Usman Butt ◽  
Shafqat Hussain ◽  
Stephan Schacht ◽  
Uwe Ritschel
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Turbine ◽  
Critical Region ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Experimental Investigations ◽  
Wind Turbine Blades

Experimental investigations of wind turbine blades having NACA airfoils 0021 and 4412 with and without tubercles on the leading edge have been performed in a wind tunnel. It was found that the lift coefficient of the airfoil 0021 with tubercles was higher at Re = 1.2×105 and 1.69×105 in post critical region (at higher angle of attach) than airfoils without tubercles but this difference relatively diminished at higher Reynolds numbers and beyond indicating that there is no effect on the lift coefficients of airfoils with tubercles at higher Reynolds numbers whereas drag coefficient remains unchanged. It is noted that at Re = 1.69×105, the lift coefficient of airfoil without tubercles drops from 0.96 to 0.42 as the angle of attack increases from 15° to 20° which is about 56% and the corresponding values of lift coefficient for airfoil with tubercles are 0.86 and 0.7 at respective angles with18% drop.

scholarly journals Development of a Technique and Method of Testing Aircraft Models with Turboprop Engine Simulators in a Small-scale Wind Tunnel - Results of Tests

10.14311/530 ◽  
2004 ◽  
Vol 44 (2) ◽  
Author(s):  
A. V. Petrov ◽  
Y. G. Stepanov ◽  
M. V. Shmakov
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Characteristics ◽  
Static Stability ◽  
Light Transport ◽  
Experimental Investigations ◽  
Small Scale ◽  
Left Hand ◽  
Aircraft Model ◽  
Turboprop Engine ◽  
Control Surfaces

This report presents the results of experimental investigations into the interaction between the propellers (Ps) and the airframe of a twin-engine, twin-boom light transport aircraft with a Π-shaped tail. An analysis was performed of the forces and moments acting on the aircraft with rotating Ps. The main features of the methodology for windtunnel testing of an aircraft model with running Ps in TsAGI’s T-102 wind tunnel are outlined.The effect of 6-blade Ps slipstreams on the longitudinal and lateral aerodynamic characteristics as well as the effectiveness of the control surfaces was studied on the aircraft model in cruise and takeoff/landing configurations. The tests were conducted at flow velocities of V∞ = 20 to 50 m/s in the ranges of angles of attack α =  -6 to 20 deg, sideslip angles of β = -16 to 16 deg and blade loading coefficient of B 0 to 2.8. For the aircraft of unusual layout studied, an increase in blowing intensity is shown to result in decreasing longitudinal static stability and significant asymmetry of the directional stability characteristics associated with the interaction between the Ps slipstreams of the same (left-hand) rotation and the empennage.

scholarly journals A unified method of identification and optimization of airfoils for aircrafts, turbine and compressor blades

2016 ◽  
Vol 2 (3(4)) ◽  
pp. 2
Author(s):  
Stanisław Ziętarski ◽  
Stanisław Kachel ◽  
Adam Kozakiewicz
Keyword(s):  
Wind Tunnel ◽  
Gas Flow ◽  
Parametric Design ◽  
Research Work ◽  
Integrated System ◽  
Turbine Engines ◽  
Compressor Blades ◽  
Specialized Software ◽  
Develop Software ◽  
Lift And Drag

Topics below are rather undesired, but important, outcome not yet completed research on the aircraft airfoils, turbine and compressor blades, parametric design of airfoils, establishing the relationships based on the results of experiments in a wind tunnel, developing databases for determining the relationships between airfoil parameters and lift and drag coefficients. Reliable database created as a result of the research work allows to simulate the wind tunnel. Very early on, however, was necessary to extend the developed specialized software for a new applications, and it meant the need for generalization of software, e.g. for gas turbine engines, propellers, etc. But after some time it turned out, that in order to achieve the required accuracy, the changes are needed in the underlying assumptions, set decades ago. In addition, coordinate measuring machines and systems, and associated software were not always as accurate as expected. Concepts how to solve it and develop software carrying out these tasks are presented in the article. It is like to withdraw from the old path and look for a new path that will lead to the reliable data base. Processes related to air or gas flow should be similarly defined in all the specialized software applications (e.g. aircrafts and turbine engines). Accuracy (10-9 mm) achieved in virtual measurements within the integrated system can be used to verify the results of CMM and other measuring systems, provided that an appropriate software has been developed.

A Roundabout for Studying Sustained Flight of Locusts

1952 ◽  
Vol 29 (2) ◽  
pp. 211-219 ◽  
Author(s):  
AUGUST KROGH ◽  
TORKEL WEIS-FOGH
Keyword(s):  
Wind Tunnel ◽  
External Factors ◽  
Flight Performance ◽  
Average Speed ◽  
Preliminary Results ◽  
Air Resistance

A roundabout technique is described which makes it possible to study the flight performance of a small ‘swarm’ of locusts (up to thirty-two individuals) for hours at a time. The resistance of the roundabout was compensated by means of a mill so that the locusts only had to overcome their own air resistance. The speed of the revolving periphery therefore equalled the preferred average flying speed of the suspended locusts. The average speed during a period, as well as the variation in speed in the course of an experiment, were found to be the same in the roundabout and in experiments where single locusts flew in front of a wind tunnel. In the latter case the insects flew in completely normal flight posture. It was concluded that the results obtained with the roundabout were as valid as the results obtained with a wind tunnel. Some preliminary results are given on the influence of different external factors on the flying speed and the ability to endure sustained flight.

Effect of Shallow Water on a Mathematical Hull at High Subcritical and Supercritical Speeds

1986 ◽  
Vol 30 (02) ◽  
pp. 85-93
Author(s):  
A. Millward ◽  
M. G. Bevan
Keyword(s):  
Shallow Water ◽  
Wave Theory ◽  
Hull Form ◽  
Towing Tank ◽  
Resistance Peak ◽  
Good Agreement ◽  
Made In

Experiments have been made in a towing tank to measure the resistance of a mathematical hull form in deepwater and in shallow water at high subcritical and supercritical speeds. The data have been compared with calculations using linearized wave theory for the same hull shape. The results have shown fairly good agreement, with the greatest differences occurring near the subcritical resistance peak.

Experimental Analysis of Five Keel-Hull Combinations

1985 ◽  
Author(s):  
J. Gerritsma ◽  
J. A. Keuning
Keyword(s):  
Experimental Analysis ◽  
Model Tests ◽  
Experimental Results ◽  
Forward Speed ◽  
Hull Form ◽  
Towing Tank ◽  
Side Force ◽  
Performance Predictions

Model tests with five different keels in combination with one particular hull form have been carried out in the Delft Towing Tank. The variations include a plain deep keel, a keel-centre board, a plain restricted draft keel,a "Scheel" keel and a "winglet" keel. Based on the experimental results performance predictions are given for a 63 ft yacht for windspeeds up to 25 knots. The measured side force and resistance as a function of heeling angle, leeway angle and forward speed are used to analyse the relative merits of the considered keel-hull combinations.

scholarly journals COMPARISON OF TESTING RESULTS OF THREE POORLY STREAMLINED ENTERTAINMENT VENUES / TRIJŲ SUDĖTINGO PAVIDALO PRAMOGINIŲ STATINIŲ MAKETŲ BANDYMŲ REZULTATŲ GRETINIMAS

2012 ◽  
Vol 18 (2) ◽  
pp. 277-289 ◽  
Author(s):  
Roman M. Pavlovsky ◽  
Igor M. Lebedich ◽  
Michail Samofalov ◽  
Valerij V. Orliansky
Keyword(s):  
Wind Tunnel ◽  
Physical Models ◽  
Experimental Investigations ◽  
Design Codes ◽  
Model Surface ◽  
Testing Conditions ◽  
Test Conditions ◽  
Aerodynamic Properties ◽  
Unique Shape ◽  
Functional Purpose

The article discusses experimental investigations of wind effects and use of design codes for solving aerodynamic problems. It provides data regarding wind-tunnel tests conducted on three buildings with poorly streamlined shapes, including: methodology and test conditions, aerodynamic properties of the designed structures, features of physical models and research results. All three civil buildings are multi-purpose stadiums of the European level. Despite the identical functional purpose, each building has a unique shape and volume. The paper analyses and compares testing conditions in the wind tunnel and some selective results. The authors propose a criterion for estimating aerodynamic properties of the overhanging roof over spectator stands. The article also considers dependencies of model surface pressures on airflow directions under various test conditions. Santrauka Darbe trumpai apžvelgti vėjo poveikių eksperimentiniai tyrimai ir projektavimo normų taikymas aerodinamikos uždaviniams spręsti. Pateikti duomenys apie trijų sudėtingo pavidalo statinių maketų eksperimentinius tyrimus aero-dinaminiame vamzdyje: metodika ir bandymų sąlygos, projektuojamų statinių aerodinaminės savybės, ypatingi maketų bruožai, bandymų rezultatai. Visi trys statiniai – europinio lygio universalieji stadionai. Nepaisant bendrosios funkcinės paskirties, kiekvieno statinio pavidalas ir tūrinis sprendinys yra originalūs. Darbe gretinamos bandymų sąlygos ir pasirinktiniai rezultatai, pasiūlytas sportinių ir pramoginių statinių gembinio stogo virš žiūrovų tribųnų aerodinaminių savybių nagrinejimo kriterijus. Išanalizuotos slėgio ant maketų paviršių priklausomybės nuo oro srauto krypties, esant įvairiems bandymų variantams.

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