Experimental Testing of an Airframe-Integrated Three-Dimensional Scramjet at Mach 10

AIAA Journal ◽  
2015 ◽  
Vol 53 (11) ◽  
pp. 3196-3207 ◽  
Author(s):  
Luke J. Doherty ◽  
Michael K. Smart ◽  
David J. Mee
Keyword(s):  
Experimental Testing ◽  
Three Dimensional ◽  
Mach 10

Experimental and numerical determination of mode II fracture toughness of woven composites verified through unidirectional composite test data

2019 ◽  
Vol 27 (9) ◽  
pp. 557-566
Author(s):  
Rowan Healey ◽  
Nabil M Chowdhury ◽  
Wing Kong Chiu ◽  
John Wang
Keyword(s):  
Fracture Toughness ◽  
Displacement Field ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Experimental Results ◽  
Woven Composites ◽  
Mode Ii ◽  
Numerical Comparison ◽  
J Integral ◽  
Mode Ii Fracture Toughness

Due to the increase in prevalence of fibre-reinforced polymer matrix composites (FRPMC) in aircraft structures, the need for adaption of failure prediction tools such as fatigue spectra has become more pertinent. Fracture toughness is an important measure with regard to fatigue, while adequate techniques and an ASTM standard for unidirectional FRPMC exist, there are mixed opinions when investigating woven FRPMC. This study describes a three-dimensional finite element model developed to assist in determining the mode II interlaminar fracture toughness ( GIIc) of fibre-reinforced woven composites, validated by an experimental and numerical comparison of GIIc determination for unidirectional FRPMC. Experimental testing mirroring the ASTM D7905 resulted in a measure of 1176 J m−2for the unidirectional specimen, while comparisons made with the literature achieved an average value of 1459.24 J m−2or the woven specimen. Three numerical methods were employed due to their prominence in the literature: displacement field, virtual crack closure techniques and the J integral. Both the J integral and the displacement field three-dimensional models produced satisfactory unidirectional GIIc estimates of 1284 and 1116.8 J m−2, respectively. Displacement field had a 5% uncertainty in GIIc when compared with experimental results, while J integral had an approximately 8.5% uncertainty. Extending the analysis to the woven specimens, values of 1302.8 and 1465.3 J m−2were obtained from J integral and displacement field methods, respectively, both within 10% of the experimental values. Hence, numerically determined unidirectional GIIc values were verified with experimental results, leading to the successful employment and extension to woven composites which displayed similar agreement.

A Eulerian Method for Water Droplet Impingement by Means of an Immersed Boundary Technique

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Francesco Capizzano ◽  
Emiliano Iuliano
Keyword(s):  
Water Droplet ◽  
Numerical Solutions ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Immersed Boundary ◽  
Test Cases ◽  
Ice Accretion ◽  
Droplet Impingement ◽  
Protection Systems ◽  
Numerical Approaches

The estimation of water droplet impingement is the first step toward a complete ice accretion assessment. Numerical approaches are usually implied to support the experimental testing and to provide fast responses when designing ice protection systems. Basically, two different numerical methodologies can be found in literature: Lagrangian and Eulerian. The present paper describes the design and development of a tool based on a Eulerian equation set solved on Cartesian meshes by using an immersed boundary (IB) technique. The tool aims at computing the evolution of a droplet cloud and the impingement characteristics onto the exposed surfaces of an aircraft. The robustness of the methodology and the accuracy of the approach are discussed. The method is applying to classical two- and three-dimensional test cases for which experimental data are available in literature. The results are compared with both experiments and body-fitted numerical solutions.

scholarly journals Cell therapy in treatment of skin burns

2020 ◽  
Vol 1 (77) ◽  
pp. 117-124
Author(s):  
A. A. Yatsenko ◽  
S. V. Barannikov ◽  
I. Yu. Makarov ◽  
I. V. Borozda ◽  
Yu. A. Spirina
Keyword(s):  
Cell Therapy ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Skin Lesions ◽  
Efficacy And Safety ◽  
Engineering Structures ◽  
Wound Coverage ◽  
Advantages And Disadvantages ◽  
Engineered Structures

The review summarizes the results of modern research in the field of cell therapy for skin burns. The relevance of conducting these studies both in Russia and in the world is described. The methods of influence on the skin regeneration after burns in addition to cell therapy are indicated. A history reference on the development of cell therapy for burn skin lesions is given. The documents governing the conduct of cell therapy in Russia are presented. The advantages and disadvantages of cell technology using keratinocytes are described. The methods of cell therapy for skin burns using fibroblasts are analyzed. The role of three-dimensional tissue-engineered structures – scaffolds in the regeneration of the skin is described. Their classification is given by the duration of wound coverage (permanent, semi-permanent and temporary), by composition (cellular, acellular), by type of material (synthetic, biological, which are divided into allogeneic and autologous). The main representatives of each group that are used in research as therapy in the treatment of skin burns are described: Biobrane, Integra, Dermagraft, TransCyte, Hyalograft 3D, Laser skin epidermal replacement, TissueTech autograft system. The data on the experimental testing of each of the representatives are presented. The issue of improving vascularization of tissue-engineering structures using bioreactors was also raised. According to the results of the review, it was concluded that the use of three-dimensional structures in the treatment of burn skin lesions shows the greatest efficacy and safety among pronounced cell therapy options in clinical practice. At the same time, the existing drawbacks of the analyzed samples require further study and analysis.

Transient Performance Analysis of an Aero Gas Turbine Cooled Cooling Air Heat Exchanger

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Alberto Mucci ◽  
Foster Kwame Kholi ◽  
Man Yeong Ha ◽  
June Kee Min ◽  
Peeter Beecroft ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Numerical Models ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Test Range ◽  
The Past ◽  
Secondary Air ◽  
Critical Components ◽  
Cooling Air ◽  
Facility System

Abstract Aviation faces several challenges to maintain growth while adapting to an environmentally viable footprint. Increasing efficiency, which in the past induced a steady rise in the turbine entry temperatures, requires successful cooling of critical components to relieve the combined effects of higher temperatures and pressures. Starting with a conceptual design that alters the flow path of the secondary air system to divert bled air into a heat exchanger, this research focuses on assessing the effects of actual flight conditions on a cooled cooling air (CCA) system. In particular, the study undertakes a transient analysis of the CCA heat exchanger under a stressful temperature increase. The performance of the unit from idle to max take off (MTO) conditions required a unique facility for experimental testing, also capable of reaching and sustaining the necessary specifications. The novelty of the concept compelled the development of numerical models to aid the design and evaluation of the experiment. These models use one- and three-dimensional techniques to perform preemptive analysis of the test range, to ensure safety during the actual test, and to provide valuable information about the facility system and the inner flow structure of the heat exchanger. The study completed successful experiments using numerically generated procedures. A back-to-back configuration, representative of multiple installations, offers evidence about the cross-influence of each heat exchanger. The research also examined the dynamic effects to provide the bases for further studies focusing on this topic.

Enhanced Collapse Resistance of Compressed Steel Pipes

2014 ◽  
Author(s):  
Venkat R. Krishnan ◽  
David A. Baker
Keyword(s):  
Experimental Testing ◽  
Three Dimensional ◽  
External Pressure ◽  
Combined Loading ◽  
Finite Element Analyses ◽  
Forming Process ◽  
3D Finite Element ◽  
Steel Pipes ◽  
Collapse Resistance ◽  
Sensitivity Studies

Pipe collapse is a primary design consideration for deep water locations and offshore areas with sharp seabed curvatures or spans, where bending reduces collapse resistance due to ovalization. Previous numerical and experimental work has shown that collapse resistance of steel pipes can be enhanced significantly by using compression instead of expansion during the final stage of the pipe forming process. ExxonMobil has recently undertaken a rigorous numerical modeling and experimental testing program to investigate the collapse resistance of compressed (JCOC) steel pipes under combined loading of external pressure and bending, and this paper presents the main results from the program. The first part of the paper presents results of sensitivity studies from three dimensional (3D) finite element analyses (FEA) of the pipe forming process, and the second part focuses on the collapse modeling under combined loading as well as a comparison of the numerical results with the experiments. The results indicate that the collapse envelope for steel pipes under combined external pressure and bending can be enhanced by up to 35% by adopting pipe compression rather than expansion as the final step of the forming process.

Experimental Testing and Finite Element Modeling of Bump Wafer Probing

2013 ◽  
Vol 284-287 ◽  
pp. 748-753
Author(s):  
Hao Yuan Chang ◽  
Kao Hua Chang ◽  
Yi Shao Lai
Keyword(s):  
Finite Element ◽  
Solder Bump ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Element Model ◽  
Simulation Software ◽  
Experimental Results ◽  
Height Variation ◽  
Bump Height ◽  
Wafer Probing

The purpose of this paper is mainly to develop a method to simulate the bump height variation and probe mark profile for Eutectic (Sn63/ Pb37) bump wafer probing with continuing-touchdown probing. Certainly, the bump height variation and probe mark area on the solder bump influence the quality of the wafer probing and further impacts reliability of the packaging process after wafer probing to cause issues of cold-joint and needle damage. A three-dimensional computational model of was developed to analyze the contact phenomena between the vertical needle and the solder bump. Finite element simulation software, ANSYS, is used to analyze the loading force distributed on the vertical needle with various overdrives. In addition, the results of the bump height variation and probe mark area, which predicted by the finite element method (FEM), were verified against the on-line experimental results. Finally, the results predicted by the finite element model is consistent with experimental results and the numerical method presented in the paper can be used as a useful evaluating method to support the choice of suitable probe geometry and wafer probe testing parameters.

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