ORCID Profile
0000-0002-9179-0321
Current Organisations
University of Sydney
,
University of New South Wales Canberra
,
UNSW Canberra
,
University of Oxford
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Publisher: Springer Science and Business Media LLC
Date: 20-05-2019
DOI: 10.1038/S41588-019-0438-3
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Publisher: Springer Science and Business Media LLC
Date: 06-2015
Publisher: Elsevier BV
Date: 10-2015
Publisher: Public Library of Science (PLoS)
Date: 12-03-2013
Publisher: Springer Science and Business Media LLC
Date: 14-11-2022
Publisher: American Physical Society (APS)
Date: 28-06-2017
Publisher: Springer Science and Business Media LLC
Date: 31-08-2011
DOI: 10.1038/NATURE10406
Publisher: Cold Spring Harbor Laboratory
Date: 21-07-2022
DOI: 10.1101/2022.07.20.500802
Abstract: Most genome-wide association studies (GWAS) of major depression (MD) have been conducted in s les of European ancestry. Here we report a multi-ancestry GWAS of MD, adding data from 21 studies with 88,316 MD cases and 902,757 controls to previously reported data from in iduals of European ancestry. This includes s les of African (36% of effective s le size), East Asian (26%) and South Asian (6%) ancestry and Hispanic/Latinx participants (32%). The multi-ancestry GWAS identified 190 significantly associated loci, 53 of them novel. For previously reported loci from GWAS in European ancestry the power-adjusted transferability ratio was 0.6 in the Hispanic/Latinx group and 0.3 in each of the other groups. Fine-mapping benefited from additional s le ersity: the number of credible sets with ≤5 variants increased from 3 to 12. A transcriptome-wide association study identified 354 significantly associated genes, 205 of them novel. Mendelian Randomisation showed a bidirectional relationship with BMI exclusively in s les of European ancestry. This first multi-ancestry GWAS of MD demonstrates the importance of large erse s les for the identification of target genes and putative mechanisms.
Publisher: Oxford University Press (OUP)
Date: 16-05-2012
DOI: 10.1093/HMG/DDS187
Publisher: Cambridge University Press (CUP)
Date: 31-03-2014
DOI: 10.1017/JFM.2014.132
Abstract: A combination of cross-wire probes with an array of flush-mounted skin-friction sensors are used to study the three-dimensional conditional organisation of large-scale structures in a high-Reynolds-number turbulent boundary layer. Previous studies have documented the litude modulation of small-scale motions in response to conditionally averaged large-scale events, but the data are largely restricted to the streamwise component of velocity alone. Here, we report results based on all three components of velocity and find that the small-scale spanwise and wall-normal fluctuations ( $v$ and $w$ ) and the instantaneous Reynolds shear stress ( $-{uw}$ ) are modulated in a very similar manner to that previously noted for the streamwise fluctuations ( $u$ ). The envelope of the small scale fluctuations for all velocity components is well described by the large-scale component of the $u$ fluctuation. These results also confirm the conditional existence of roll modes associated with the very large-scale or ‘superstructure’ motions.
Publisher: Research Square Platform LLC
Date: 29-07-2022
DOI: 10.21203/RS.3.RS-1832470/V1
Abstract: Genome-wide association studies (GWAS) in predominately European-ancestry (EUR) populations have identified numerous genetic variants associated with adiposity-related traits. An emerging challenge is the limited transferability of genetic scores constructed based on GWAS results from one ancestry for trait prediction in other ancestries. We performed trans-ancestry meta-analysis (TAMA) for eight adiposity-related traits using genetic data from 96,124 East Asian (EAS) and 443,359 EUR in iduals. We identified genomic regions significantly associated with one or more traits. Despite EAS comprising only ~20% of the study population, genetic scores constructed from the trans-ancestry (TA) results accounted for between 30% and 79% more variation in the adiposity traits in EAS compared with scores derived from the EUR GWAS alone. Furthermore, TA scores also modestly improved variance explained in African/African American, Hispanic and South Asian populations. Our findings highlight the utility of TAMA for increasing variance explained by genetic scores across populations of different ancestries.
Publisher: Cambridge University Press (CUP)
Date: 29-12-2021
DOI: 10.1017/JFM.2020.921
Publisher: Cambridge University Press (CUP)
Date: 25-01-2021
Publisher: IOP Publishing
Date: 28-11-2022
Abstract: This paper describes a large-scale visualization system that can simultaneously produce background-oriented schlieren (BOS) images and retroreflective shadowgrams (RS) of a compressible flow. The simultaneous measurements with BOS and RS in two optically equal systems allowed a direct comparison of the performance of the two methods and to quantify the relative differences, primarily with respect to identifying the broad range of length scales in a turbulent compressible flow. Further, direct comparisons are made between the schlieren image obtained from the BOS measurement, the displacement map obtained by subtracting a no-flow image from the unprocessed BOS record, the ergence of the BOS displacement field (the latter two are forms of a BOS-generated shadowgram), and the simultaneously obtained direct shadowgram from the RS setup. A qualitative comparison of the results indicated that all the three methods (BOS schlieren, direct difference, and ergence of the BOS-schlieren record) can capture the large-scale flow structures but that the smaller scales in the plume can only be resolved to a much lesser extent. These structures were, however, easily resolved in the RS images. The results show that, in the described system, the resolution of the BOS images is lower than that of the shadowgrams by a factor of about five. Further tests indicate that these differences in the spatial resolution of the BOS technique cannot be removed using a different design of the random-dot background pattern. These observations apply to the used large-scale system in which a minimum distance between the observed object and each of the two screens (background pattern/reflective) has to be maintained. This constraint also meant that neither system could be optimized with respect to spatial resolution.
Publisher: Cold Spring Harbor Laboratory
Date: 12-03-2019
DOI: 10.1101/575167
Abstract: Miscarriage is a common complex trait that affects 10-25% of clinically confirmed pregnancies 1,2 . Here we present the first large-scale genetic association analyses with 69,118 cases from five different ancestries for sporadic miscarriage and 750 cases of European ancestry for recurrent miscarriage, and up to 359,469 female controls. We identify one genome-wide significant association on chromosome 13 (rs146350366, minor allele frequency (MAF) 1.2%, P meta =3.2× -8 (CI) 1.2-1.6) for sporadic miscarriage in our European ancestry meta-analysis (50,060 cases and 174,109 controls), located near FGF9 involved in pregnancy maintenance 3 and progesterone production 4 . Additionally, we identified three genome-wide significant associations for recurrent miscarriage, including a signal on chromosome 9 (rs7859844, MAF=6.4%, P meta =1.3× -8 in controlling extravillous trophoblast motility 5 . We further investigate the genetic architecture of miscarriage with biobank-scale Mendelian randomization, heritability and, genetic correlation analyses. Our results implicate that miscarriage etiopathogenesis is partly driven by genetic variation related to gonadotropin regulation, placental biology and progesterone production.
Publisher: Cambridge University Press (CUP)
Date: 27-04-2022
DOI: 10.1017/JFM.2022.292
Abstract: Experiments are carried out on a turbulent fountain to investigate the entrainment of ambient fluid and the dilution of scalar concentration in the fountain top (also referred to as the ‘cap’). The source Froude number ( $Fr_o$ ), defined based on the density difference between the source and the ambient fluids, is varied between 10 and 30, while the Reynolds number ( $Re_o$ ) is set to a minimum of 3000 to ensure a fully turbulent flow at the source. High-fidelity velocity and concentration measurements are obtained using particle image velocimetry and planar laser induced fluorescence techniques, respectively. The mean concentration field indicates that the cap is approximately hemispherical and its base is characterised by the local Froude number $Fr_z \\approx 1.5$ . It is observed that the ratio of the entrained ( $Q_{top}$ ) volume flux in the fountain top and the volume flux supplied ( $Q_{in}$ ) at the base of the cap varies between 1.5 and 3.5 at different $Fr_o$ , exceeding the values of $Q_{top}/Q_{in} (= 0.5\\text {--}0.8)$ for a fountain developing across a density interface (Lin & Linden, J. Fluid Mech. , vol. 542, 2005, pp. 25–52). The present experimental results for $Q_{top}/Q_{in}$ are in excellent agreement with published numerical simulations of turbulent fountains at similar $Fr_o$ . Lastly, a robust metric to estimate the dilution of scalar in the fountain top has been proposed. The results clearly indicate that dilution is not equal to the entrainment ratio however, the self-similarity of non-dimensional dilution profiles at different $Fr_o$ suggests that the phenomenological model for entrainment in the fountain top put forth by Debugne & Hunt ( J. Fluid Mech. , vol. 796, 2016, pp. 195–210), can also be effectively used to model the dilution of scalar concentration in the cap. Further, it is found that the variation of the dilution ratio is closely linked to the local Reynolds number ( $Re_z$ ) at the base of the cap. This is verified using an analytical model that describes the dependency of $Re_z$ on the local and source parameters – $Fr_z$ , $Re_o$ and $Fr_o$ .
Publisher: Oxford University Press (OUP)
Date: 05-05-2011
DOI: 10.1093/BIOINFORMATICS/BTR264
Abstract: Summary: A program package to enable genome-wide association of copy number variants (CNVs) with quantitative phenotypes in families of arbitrary size and complexity. Intensity signals that act as proxies for the number of copies are modeled in a variance component framework and association with traits is assessed through formal likelihood testing. Availability and implementation: The Java package is made available at www.imperial.ac.uk/medicine eople/m.falchi/. Contact: m.falchi@imperial.ac.uk
Publisher: Springer Science and Business Media LLC
Date: 02-2010
DOI: 10.1038/NATURE08727
Publisher: Cambridge University Press (CUP)
Date: 22-12-2016
DOI: 10.1017/JFM.2015.665
Abstract: A self-preservation (SP) analysis is carried out for a zero pressure gradient (ZPG) rough-wall turbulent boundary layer with a view to establishing the requirements of complete SP (i.e. SP across the entire layer) and determining if these are achievable. The analysis shows that SP is achievable in certain rough-wall boundary layers (irrespectively of the Reynolds number $Re$ ), when the mean viscous stress is zero or negligible compared to the form drag across the entire boundary layer. In this case, the velocity scale $u^{\\ast }$ must be constant, the length scale $l$ should vary linearly with the streamwise distance $x$ and the roughness height $k$ must be proportional to $l$ . Although this result is consistent with that of Rotta ( Prog. Aeronaut. Sci. , vol. 2 (1), 1962, pp. 1–95), it is derived in a more rigorous manner than the method employed by Rotta. Further, it is noted that complete SP is not possible in a smooth-wall ZPG turbulent boundary layer. The SP conditions are tested against published experimental data on both a smooth wall (Kulandaivelu, 2012, PhD thesis, The University of Melbourne) and a rough wall, where the roughness height increases linearly with $x$ (Kameda et al. , J. Fluid Sci. Technol. , vol. 3 (1), 2008, pp. 31–42). Complete SP in a ZPG rough-wall turbulent boundary layer seems indeed possible when $k\\propto x$ .
Publisher: IOP Publishing
Date: 28-03-2017
Publisher: Springer Science and Business Media LLC
Date: 24-09-2019
DOI: 10.1038/S41467-019-12026-7
Abstract: Most genome-wide association studies are based on s les of European descent. We assess whether the genetic determinants of blood lipids, a major cardiovascular risk factor, are shared across populations. Genetic correlations for lipids between European-ancestry and Asian cohorts are not significantly different from 1. A genetic risk score based on LDL-cholesterol-associated loci has consistent effects on serum levels in s les from the UK, Uganda and Greece ( r = 0.23–0.28, p 1.9 × 10 −14 ). Overall, there is evidence of reproducibility for ~75% of the major lipid loci from European discovery studies, except triglyceride loci in the Ugandan s les (10% of loci). In idual transferable loci are identified using trans-ethnic colocalization. Ten of fourteen loci not transferable to the Ugandan population have pleiotropic associations with BMI in Europeans none of the transferable loci do. The non-transferable loci might affect lipids by modifying food intake in environments rich in certain nutrients, which suggests a potential role for gene-environment interactions.
Publisher: Public Library of Science (PLoS)
Date: 29-08-2008
Publisher: IOP Publishing
Date: 31-05-2019
Publisher: Springer Science and Business Media LLC
Date: 30-05-2010
DOI: 10.1038/NMETH.1466
Abstract: Although genome-wide association studies have uncovered single-nucleotide polymorphisms (SNPs) associated with complex disease, these variants account for a small portion of heritability. Some contribution to this 'missing heritability' may come from copy-number variants (CNVs), in particular rare CNVs but assessment of this contribution remains challenging because of the difficulty in accurately genotyping CNVs, particularly small variants. We report a population-based approach for the identification of CNVs that integrates data from multiple s les and platforms. Our algorithm, cnvHap, jointly learns a chromosome-wide haplotype model of CNVs and cluster-based models of allele intensity at each probe. Using data for 50 French in iduals assayed on four separate platforms, we found that cnvHap correctly detected at least 14% more deleted and 50% more lified genotypes than PennCNV or QuantiSNP, with an 82% and 115% improvement for aberrations containing <10 probes. Combining data from multiple platforms additionally improved sensitivity.
Publisher: Springer Science and Business Media LLC
Date: 22-12-2020
Publisher: Springer Science and Business Media LLC
Date: 05-2016
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 18-10-2022
DOI: 10.1212/WNL.0000000000201006
Abstract: Current genome-wide association studies of ischemic stroke have focused primarily on late-onset disease. As a complement to these studies, we sought to identify the contribution of common genetic variants to risk of early-onset ischemic stroke. We performed a meta-analysis of genome-wide association studies of early-onset stroke (EOS), ages 18–59 years, using in idual-level data or summary statistics in 16,730 cases and 599,237 nonstroke controls obtained across 48 different studies. We further compared effect sizes at associated loci between EOS and late-onset stroke (LOS) and compared polygenic risk scores (PRS) for venous thromboembolism (VTE) between EOS and LOS. We observed genome-wide significant associations of EOS with 2 variants in ABO , a known stroke locus. These variants tag blood subgroups O1 and A1, and the effect sizes of both variants were significantly larger in EOS compared with LOS. The odds ratio (OR) for rs529565, tagging O1, was 0.88 (95% confidence interval [CI]: 0.85–0.91) in EOS vs 0.96 (95% CI: 0.92–1.00) in LOS, and the OR for rs635634, tagging A1, was 1.16 (1.11–1.21) for EOS vs 1.05 (0.99–1.11) in LOS p -values for interaction = 0.001 and 0.005, respectively. Using PRSs, we observed that greater genetic risk for VTE, another prothrombotic condition, was more strongly associated with EOS compared with LOS ( p = 0.008). The ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with EOS than with LOS, supporting a stronger role of prothrombotic factors in EOS.
Publisher: Cold Spring Harbor Laboratory
Date: 07-07-2022
DOI: 10.1101/2022.07.05.22277254
Abstract: Genome-wide association studies (GWAS) in predominately European-ancestry (EUR) populations have identified numerous genetic variants associated with adiposity-related traits. An emerging challenge is the limited transferability of genetic scores constructed based on GWAS results from one ancestry for trait prediction in other ancestries. We performed trans-ancestry meta-analysis (TAMA) for eight adiposity-related traits using genetic data from 96,124 East Asian (EAS) and 443,359 EUR in iduals. We identified genomic regions significantly associated with one or more traits. Despite EAS comprising only ∼20% of the study population, genetic scores constructed from the trans-ancestry (TA) results accounted for between 30% and 79% more variation in the adiposity traits in EAS compared with scores derived from the EUR GWAS alone. Furthermore, TA scores also modestly improved variance explained in African/African American, Hispanic and South Asian populations. Our findings highlight the utility of TAMA for increasing variance explained by genetic scores across populations of different ancestries.
Publisher: Elsevier BV
Date: 2022
Publisher: Cold Spring Harbor Laboratory
Date: 28-04-2023
DOI: 10.1101/2023.04.28.23289268
Abstract: Although it is known that variation in the aldehyde dehydrogenase 2 ( ALDH2 ) gene family influences the East Asian alcohol flushing response, knowledge about other genetic variants that affect flushing symptoms is limited. We performed a genome-wide association study meta-analysis and heritability analysis of alcohol flushing in 15,105 males of East Asian ancestry (Koreans and Chinese) to identify genetic associations with alcohol flushing. We also evaluated whether self-reported flushing can be used as an instrumental variable for alcohol intake. We identified variants in the region of ALDH2 strongly associated with alcohol flushing, replicating previous studies conducted in East Asian populations. Additionally, we identified variants in the alcohol dehydrogenase 1B ( ADH1B ) gene region associated with alcohol flushing. Several novel variants were identified after adjustment for the lead variants ( ALDH2 -rs671 and ADH1B -rs1229984), which need to be confirmed in larger studies. The estimated SNP-heritability on the liability scale was 13% (S.E. = 4%) for flushing, but the heritability estimate decreased to 6% (S.E. = 4%) when the effects of the lead variants were controlled for. Genetic instrumentation of higher alcohol intake using these variants recapitulated known associations of alcohol intake with hypertension. Using self-reported alcohol flushing as an instrument gave a similar association pattern of higher alcohol intake and cardiovascular disease-related traits (e.g. stroke). This study confirms that ALDH2 -rs671 and ADH1B -rs1229984 are associated with alcohol flushing in East Asian populations. Our findings also suggest that self-reported alcohol flushing can be used as an instrumental variable in future studies of alcohol consumption. This study only used secondary data.
Publisher: Springer Berlin Heidelberg
Date: 13-11-2013
Publisher: Springer Science and Business Media LLC
Date: 25-02-2019
Publisher: Cold Spring Harbor Laboratory
Date: 08-11-2021
DOI: 10.1101/2021.11.06.21265795
Abstract: To determine the contribution of common genetic variants to risk of early onset ischemic stroke (IS). We performed a meta-analysis of genome-wide association studies of early onset IS, ages 18-59, using in idual level data or summary statistics in 16,927 cases and 576,353 non-stroke controls from 48 different studies across North America, Europe, and Asia. We further compared effect sizes at our most genome-wide significant loci between early and late onset IS and compared polygenic risk scores for venous thromboembolism between early versus later onset IS. We observed an association between early onset IS and ABO , a known stroke locus. The effect size of the peak ABO SNP, rs8176685, was significantly larger in early compared to late onset IS (OR 1.17 (95% C.I.: 1.11-1.22) vs 1.05 (0.99-1.12) p for interaction = 0.008). Analysis of genetically determined ABO blood groups revealed that early onset IS cases were more likely to have blood group A and less likely to have blood group O compared to both non-stroke controls and to late onset IS cases. Using polygenic risk scores, we observed that greater genetic risk for venous thromboembolism, another prothrombotic condition, was more strongly associated with early, compared to late, onset IS (p=0.008). The ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with early onset IS, compared with late onset IS, supporting a stronger role of prothrombotic factors in early onset IS.
Publisher: IOP Publishing
Date: 25-06-2019
Publisher: IOP Publishing
Date: 15-09-2014
Publisher: Springer Science and Business Media LLC
Date: 23-09-2015
Publisher: Springer Science and Business Media LLC
Date: 16-11-2020
Publisher: Cambridge University Press (CUP)
Date: 14-05-2019
DOI: 10.1017/JFM.2019.253
Abstract: Measurements of concentration fluctuations in a passive scalar plume released within a turbulent boundary layer are utilised to ascertain the scaling of concentration spectra. It is observed that the concentration spectra in a narrow meandering plume has a self-similar behaviour in both transverse ( $y$ ) and vertical ( $z$ , i.e. wall-normal) directions. Experimental data reveal self-similarity when the magnitude of concentration spectra is scaled by the local concentration variance whereas frequency is suitably scaled utilising the integral length scale of the streamwise velocity or the boundary layer thickness and the source velocity as length and velocity scales, respectively. Furthermore, our data show that at each frequency, the concentration energy is distributed across the $y$ and $z$ directions that is proportional to concentration variance at that location. These results are consistent with our non-dimensional analysis. Based on these observations, if the mean plume statistics are known, a model is proposed with which concentration spectrum at any position within the plume can be calculated using the spectrum at any another location as the input. The model is tested extensively for point-source plumes released at various heights and streamwise distances in a turbulent boundary layer, and is found to predict spectra at different $y$ and $z$ locations in close agreement with measurements.
Publisher: Springer Science and Business Media LLC
Date: 25-11-2020
DOI: 10.1038/S41467-020-19742-5
Abstract: Miscarriage is a common, complex trait affecting ~15% of clinically confirmed pregnancies. Here we present the results of large-scale genetic association analyses with 69,054 cases from five different ancestries for sporadic miscarriage, 750 cases of European ancestry for multiple (≥3) consecutive miscarriage, and up to 359,469 female controls. We identify one genome-wide significant association (rs146350366, minor allele frequency (MAF) 1.2%, P = 3.2 × 10 −8 , odds ratio (OR) = 1.4) for sporadic miscarriage in our European ancestry meta-analysis and three genome-wide significant associations for multiple consecutive miscarriage (rs7859844, MAF = 6.4%, P = 1.3 × 10 −8 , OR = 1.7 rs143445068, MAF = 0.8%, P = 5.2 × 10 −9 , OR = 3.4 rs183453668, MAF = 0.5%, P = 2.8 × 10 −8 , OR = 3.8). We further investigate the genetic architecture of miscarriage with biobank-scale Mendelian randomization, heritability, and genetic correlation analyses. Our results show that miscarriage etiopathogenesis is partly driven by genetic variation potentially related to placental biology, and illustrate the utility of large-scale biobank data for understanding this pregnancy complication.
Publisher: Cambridge University Press (CUP)
Date: 18-07-2018
DOI: 10.1017/JFM.2018.460
Abstract: This paper examines the Reynolds number ( $Re$ ) dependence of a zero-pressure-gradient (ZPG) turbulent boundary layer (TBL) which develops over a two-dimensional rough wall with a view to ascertaining whether this type of boundary layer can become independent of $Re$ . Measurements are made using hot-wire anemometry over a rough wall that consists of a periodic arrangement of cylindrical rods with a streamwise spacing of eight times the rod diameter. The present results, together with those obtained over a sand-grain roughness at high Reynolds number, indicate that a $Re$ -independent state can be achieved at a moderate $Re$ . However, it is also found that the mean velocity distributions over different roughness geometries do not collapse when normalised by appropriate velocity and length scales. This lack of collapse is attributed to the difference in the drag coefficient between these geometries. We also show that the collapse of the $U_{\\unicode[STIX]{x1D70F}}$ -normalised mean velocity defect profiles may not necessarily reflect $Re$ -independence. A better indicator of the asymptotic state of $Re$ is the mean velocity defect profile normalised by the free-stream velocity and plotted as a function of $y/\\unicode[STIX]{x1D6FF}$ , where $y$ is the vertical distance from the wall and $\\unicode[STIX]{x1D6FF}$ is the boundary layer thickness. This is well supported by the measurements.
Publisher: Springer Science and Business Media LLC
Date: 06-02-2017
DOI: 10.1038/NG.3787
Publisher: Cambridge University Press (CUP)
Date: 04-05-2018
DOI: 10.1017/JFM.2018.280
Abstract: Simultaneous measurements of streamwise velocity ( $\\tilde{U}$ ) and concentration ( $\\tilde{C}$ ) for a horizontal plume released at eight different vertical locations within a turbulent boundary layer are discussed in this paper. These are supplemented by limited simultaneous three-component velocity and concentration measurements. Results of the integral time scale ( $\\unicode[STIX]{x1D70F}_{c}$ ) of concentration fluctuations across the width of the plume are presented here for the first time. It is found that $\\unicode[STIX]{x1D70F}_{c}$ has two distinct peaks: one closer to the plume centreline and the other at a vertical distance of plume half-width above the centreline. The time-averaged streamwise concentration flux is found to be positive and negative, respectively, below and above the plume centreline. This behaviour is a resultant of wall-normal velocity fluctuations ( $w$ ) and Reynolds shear stress ( $\\overline{uw}$ ). Confirmation of these observations is found in the results of joint probability density functions of $u$ (streamwise velocity fluctuations) and $\\tilde{C}$ as well as that of $w$ and $\\tilde{C}$ . Results of cross-correlation coefficient show that high- and low-momentum regions have a distinctive role in the transport of passive scalar. Above the plume centreline, low-speed structures have a lead over the meandering plume, while high-momentum regions are seen to lag behind the plume below its centreline. Further examination of the phase relationship between time-varying $u$ and $c$ (concentration fluctuations) via cross-spectrum analysis is consistent with this observation. Based on these observations, a phenomenological model is presented for the relative arrangement of a passive scalar plume with respect to large-scale velocity structures in the flow.
Publisher: American Institute of Aeronautics and Astronautics (AIAA)
Date: 03-2023
DOI: 10.2514/1.J061886
Abstract: This paper reports experimental results of fluid/structure interactions induced by shock impingement on a cl ed-free/cl ed-free compliant panel in a Mach 5.8 Ludwieg tube. A shock generator is used to statically impinge a shock on the panel with the aim of producing flow-induced vibrations. In turn, these vibrations create an aeroelastic coupling between the panel and the flowfield, which is dominated by the shock-wave/boundary-layer interactions. The influence of the structural compliance and shock impingement strength is assessed by testing a nominally rigid panel and compliant panels with thickness-to-length ratios of 0.0034 and 0.0068 with a shock generator at flow deflection angles of 0, 2, 3, 8, and 10 deg. One of the primary findings of the present work is that the aeroelastic response of the panel tends to shift from a structurally dominated to a fluid-dominated regime, which is sustained by either the freestream fluctuations or the fluid/structure coupling, depending on the structural compliance and shock impingement strength and location. This work is of fundamental nature, and its main goal is to analyze the interactions between high-speed flow and a thin compliant panel of canonical geometry. However, studies like this are crucial to characterize those complex couplings and provide experimental data that can help enhance the accuracy of aeroelastic modeling tools that feed into the design process of supersonic and hypersonic airframes.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Robin Walters.