scholarly journals Assessment of high enthalpy flow conditions for re-entry aerothermodynamics in the plasma wind tunnel facilities at IRS

2021 ◽  
Author(s):  
Stefan Loehle ◽  
Fabian Zander ◽  
Martin Eberhart ◽  
Tobias Hermann ◽  
Arne Meindl ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Total Pressure ◽  
Low Earth Orbit ◽  
Specific Enthalpy ◽  
Space Systems ◽  
Flow Conditions ◽  
Experimental Conditions ◽  
High Enthalpy ◽  
The University ◽  
Boundary Layer Edge

AbstractThis article presents the full operational experimental capabilities of the plasma wind tunnel facilities at the Institute of Space Systems at the University of Stuttgart. The simulation of the aerothermodynamic environment experienced by vehicles entering the atmosphere of Earth is attempted using three different facilities. Utilizing the three different facilities, the recent improvements enable a unique range of flow conditions in relation to other known facilities. Recent performance optimisations are highlighted in this article. Based on the experimental conditions demonstrated a corresponding flight scenario is derived using a ground-to-flight extrapolation approach based on local mass-specific enthalpy, total pressure and boundary layer edge velocity gradient. This shows that the three facilities cover the challenging parts of the aerothermodynamics along the entry trajectory from Low Earth Orbit. Furthermore, the more challenging conditions arising during interplanetary return at altitudes above 70 km are as well covered.

On the Response of Horizontal and Vertical Axis Wind Turbines to Turbulence: A Wind Tunnel Experiment

2014 ◽  
Author(s):  
Nicolas A. Tobin ◽  
Rishabh Narang ◽  
Leonardo P. Chamorro
Keyword(s):  
Wind Tunnel ◽  
Turbulent Flow ◽  
Vertical Axis ◽  
High Temporal Resolution ◽  
Flow Conditions ◽  
Physical Processes ◽  
University Of Illinois ◽  
Flow Modulation ◽  
Vertical Axis Wind Turbines ◽  
The University

The turbulent flow modulation on the unsteady behavior of a model VAWT is investigated and compared with a model HAWT of similar size in a laboratory experiment. The turbines operated in low and high freestream turbulence. The research was performed at the Talbot Laboratory wind tunnel at the University of Illinois at Urbana-Champaign (UIUC). High-resolution measurements of the turbine voltage for a small, 12 cm HAWT and a 16 cm VAWT are acquired at high temporal resolution, sufficient to capture the turbulent scales of flow relevant to the problem. Both turbines were built at the UIUC rapid prototyping lab and have realistic airfoil shapes. An understanding of the distinctive physical processes modulating the scale-to-scale fluctuating behavior in a VAWT and a HAWT exposed to the same turbulent flow conditions is discussed. A relation between turbulent motions and fluctuating behavior is extended from the knowledge of HAWTs to VAWTs.

Wind Tunnel Study on a Missile with Forward-Facing Cavity in Supersonic Flow

2014 ◽  
Vol 1016 ◽  
pp. 370-376
Author(s):  
Jiang Zhang ◽  
Xiao Jun Pan ◽  
Jin Gang Dong ◽  
Yong Ming Qin ◽  
Han Dong Ma
Keyword(s):  
Wind Tunnel ◽  
Total Pressure ◽  
Force Measurement ◽  
Cavity Flow ◽  
Bow Shock ◽  
Dynamic Force ◽  
Flow Conditions ◽  
Fluctuation Pressure ◽  
Wind Tunnel Study ◽  
Transonic Wind Tunnel

A forward-facing cavity will be composed of the components of a scramjet from inlet to combustion chamber which has a uncovered inlet before the separation of the booster. Longitudinal oscillations are generated within the cavity under some certain flow conditions. Strong oscillations may damage the components of the scramjet, or induce bow-shock oscillations which may cause unsteady loads on the missile and affect the performance of the aerodynamical characteristics. An experimental study of missile model with a scramjet was conducted in a transonic wind tunnel. The characteristics of cavity flow were researched by both the dynamic force measurement and the fluctuation pressure measurement. In the experiments the oscillations within the cavity and the bow-shock in front of the inlet interacted. The oscillations of cavity flow and bow-shock affected the fluctuation pressure and the aerodynamical characteristics of missile remarkably. The amplitude of axial force was higher than the normal force's. The RMS of the fluctuation pressure of some measured place inside the scramjet reached a quarter of the total pressure, and the amplitude of the fluctuation reached half of the total pressure. Those might threaten the safety of the structure of the scramjet.

Generation and Characterization of High Enthalpy CO2 Flow by Laser Driven Plasma Wind Tunnel

2013 ◽  
Author(s):  
Makoto Matsui ◽  
Shingo Yoneda ◽  
Satoshi Nomura ◽  
Yoshiki Yamagiwa ◽  
Kimiya Komurasaki ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
High Enthalpy ◽  
Co2 Flow

Utilising the EyasSAT Concept in Space Systems Engineering Courses at the University of Surrey

2006 ◽  
Author(s):  
Major David J. Barnhart ◽  
Dr. Tanya Vladimirova ◽  
Dr. Alex Ellery ◽  
Dr. Vaios J. Lappas ◽  
Dr. Craig I. Underwood ◽  
...  
Keyword(s):  
Systems Engineering ◽  
Space Systems ◽  
The University

scholarly journals 3D Acoustic Mapping in Automotive Wind Tunnel: Algorithm and Problem Analysis on Simulated Data

2021 ◽  
Vol 11 (7) ◽  
pp. 3241
Author(s):  
Gianmarco Battista ◽  
Paolo Chiariotti ◽  
Milena Martarelli ◽  
Paolo Castellini ◽  
Claudio Colangeli ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Problem Definition ◽  
Aerodynamic Noise ◽  
Accurate Information ◽  
Problem Analysis ◽  
Wind Tunnel Testing ◽  
Experimental Conditions ◽  
Automotive Manufacturing ◽  
Acoustic Mapping ◽  
Tunnel Testing

Localization and quantification of noise sources are important to fulfill customer and regulation requirements in a such competitive sector like automotive manufacturing. Wind tunnel testing and acoustic mapping techniques based on microphone arrays can provide accurate information on these aspects. However, it is not straightforward to get source positions and strengths in these testing conditions. In fact, the car is a 3D object that radiates noise from different parts simultaneously, involving different noise generation mechanisms such as tire noise and aerodynamic noise. Commonly, acoustic maps are produced on a 3D surface that envelopes the objects. However, this practice produces misleading and/or incomplete results, as acoustic sources can be generated outside the surface. When the hypothesis of sources on the model surface is removed, additional issues arise. In this paper, we propose exploiting an inverse method tailored to a volumetric approach. The aim of this paper is to investigate the issues to face when the method is applied to automotive wind tunnel testing. Two different kinds of problem must be considered: On the one hand, the results of inverse methods are strongly influenced by the problem definition, while, on the other hand, experimental conditions must be taken into account to get accurate results. These aspects have been studied making use of simulated experiments. Such a controlled simulation environment, by contrast to a purely experimental case, enables accurate assessment of both the localization and quantification performance of the proposed method. Finally, a set of scores is defined to evaluate the resulting maps with objective metrics.

Total Pressure Correction of a Sub-Miniature Five-Hole Probe in Areas of Pressure Gradients

2012 ◽  
Author(s):  
J. Town ◽  
A. Akturk ◽  
C. Camcı
Keyword(s):  
Pressure Measurement ◽  
Measurement Errors ◽  
Total Pressure ◽  
Pressure Gradients ◽  
Pressure Data ◽  
Flow Conditions ◽  
Complex Flow ◽  
Ducted Fan ◽  
The Difference ◽  
Best Fit

Five-hole probes, being a dependable and accurate aerodynamic tools, are excellent choices for measuring complex flow fields. However, total pressure gradients can induce measurement errors. The combined effect of the different flow conditions on the ports causes the measured total pressure to be prone to a greater error. This paper proposes a way to correct the total pressure measurement. The correction is based on the difference between the measured total pressure data of a Kiel probe and a sub-miniature prism-type five-hole probe. By comparing them in a ducted fan related flow field, a line of best fit was constructed. The line of best fit is dependent on the slope of the line in a total pressure versus span and difference in total pressure between the probes at the same location. A computer program, performs the comparison and creates the correction equation. The equation is subsequently applied to the five-hole probe total pressure measurement, and the other dependent values are adjusted. The validity of the correction is then tested by placing the Kiel probe and the five-hole probe in ducted fans with a variety of different tip clearances.

scholarly journals Temperature log simulations in high-enthalpy boreholes

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Jia Wang ◽  
Fabian Nitschke ◽  
Maziar Gholami Korzani ◽  
Thomas Kohl
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Temperature Gradient ◽  
Flow Rate ◽  
Fluid Loss ◽  
Flow Conditions ◽  
Flow Rates ◽  
High Enthalpy ◽  
Fluid Losses ◽  
Lateral Heat

Abstract Temperature logs have important applications in the geothermal industry such as the estimation of the static formation temperature (SFT) and the characterization of fluid loss from a borehole. However, the temperature distribution of the wellbore relies on various factors such as wellbore flow conditions, fluid losses, well layout, heat transfer mechanics within the fluid as well as between the wellbore and the surrounding rock formation, etc. In this context, the numerical approach presented in this paper is applied to investigate the influencing parameters/uncertainties in the interpretation of borehole logging data. To this end, synthetic temperature logs representing different well operation conditions were numerically generated using our newly developed wellbore simulator. Our models account for several complex operation scenarios resulting from the requirements of high-enthalpy wells where different flow conditions, such as mud injection with- and without fluid loss and shut-in, occur in the drill string and the annulus. The simulation results reveal that free convective heat transfer plays an important role in the earlier evolution of the shut-in-time temperature; high accuracy SFT estimation is only possible when long-term shut-in measurements are used. Two other simulation scenarios for a well under injection conditions show that applying simple temperature correction methods on the non-shut-in temperature data could lead to large errors for SFT estimation even at very low injection flow rates. Furthermore, the magnitude of the temperature gradient increase depends on the flow rate, the percentage of fluid loss and the lateral heat transfer between the fluid and the rock formation. As indicated by this study, under low fluid losses (< 30%) or relatively higher flow rates (> 20 L/s), the impact of flow rate and the lateral heat transfer on the temperature gradient increase can be ignored. These results provide insights on the key factors influencing the well temperature distribution, which are important for the choice of the drilling data to estimate SFT and the design of the inverse modeling scheme in future studies to determine an accurate SFT profile for the high-enthalpy geothermal environment.

Research of the flow procedures in a pressure sewer system

2003 ◽  
Vol 47 (7-8) ◽  
pp. 351-356
Author(s):  
C. Dohse ◽  
H. Eckstädt
Keyword(s):  
Land Reclamation ◽  
Flow Conditions ◽  
Sewer System ◽  
Flow Meters ◽  
Initial Information ◽  
Pressure Pipe ◽  
Pumping Stations ◽  
Hydraulic Conditions ◽  
Measuring Section ◽  
The University

At the Institute of Land Reclamation, Hydrology and Sanitary Engineering of the University at Rostock the pressure and flow ratios are examined within a measuring section in the pressure dewatering system on the Darfl peninsula. The objective of the research project is the knowledge upgrade about the highly unsteady hydraulic conditions in a pressure sewer system. This paper firstly presents the method and the dimensioning of pressure dewatering systems, which can be done using either the peak effluent method or the statistical method; the examination program will be explained. The examination includes pressure difference measuring with two pressure meters and flow data measuring via magnetic-inductive flow meters. Additionally the pump running times of 15 pumping stations, as well as the compressor action of the pressure pipe rinsing station are continuously and temporarily recorded and saved. Finally the measuring results which provide initial information about the pressure and flow conditions in a pressure dewatering system will be presented. The effects of the rinsing, the low pressure differences, the air cushions, the seasonal differences as well as the daily development graphs of the wastewater production are all clearly visible.

scholarly journals Surface Renewal as a Significant Mechanism for Dust Emission

2016 ◽  
Author(s):  
Jie Zhang ◽  
Zhenjiao Teng ◽  
Ning Huang ◽  
Lei Guo ◽  
Yaping Shao
Keyword(s):  
Wind Tunnel ◽  
Emission Rate ◽  
Dust Emission ◽  
Limit Surface ◽  
Soil Dust ◽  
Flow Conditions ◽  
Wind Tunnel Experiments ◽  
Surface Renewal ◽  
Surface Particle ◽  
Significant Mechanism

Abstract. Wind-tunnel experiments of dust emissions from different soil surfaces are carried out to better understand dust emission mechanisms. The effects of surface renewal on aerodynamic entrainment and saltation bombardment are analysed in detail, and the measurements are used to test published dust models. It is found that flow conditions, surface particle motions (saltation and creep), soil dust content and ground obstacles all strongly affect dust emission, causing dust emission rate to vary over orders of magnitude. Aerodynamic entrainment is highly effective, if dust supply is unlimited, as in the first 2–3 minutes of our wind-tunnel runs. While aerodynamic entrainment is suppressed by dust supply limit, surface renewal through the motion of surface particles is found to be an effective pathway to remove the supply limit. Surface renewal is also found to be important to the efficiency of saltation bombardment. We demonstrate that surface renewal is a significant mechanism affecting dust emission and recommend that this mechanism be included in future dust models.

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