| 1. |
- Luo, Lei, et al.
(författare)
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Computational investigation of curvature effects on jet impingement heat transfer at internally cooled turbine vane leading edge regions
- 2020
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Ingår i: Heat Transfer Research. - 1064-2285. ; 51:4, s. 333-357
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Tidskriftsartikel (refereegranskat)abstract
- This study is carried out by using numerical simulations to investigate the effect of target surface curvature and the nozzle-to-target surface distance on the flow structure and heat transfer characteristics in a pin-finned double-wall cooling structure. The flow is directly impinging on the target surface and is disturbed by the pin fins, and then released from the film holes after passing the double-wall chamber. The ratio between the radius of the concave outer surface and the chord length of the concave outer surface is varied from 0.500 to 1.300 and the ratio between nozzle-to-target surface distance and diameter of impingement hole is ranging from 0.5 to 2.0. The Reynolds number is between 10,000 and 50,000. Results of the flow structure in the chamber, heat transfer on the target surface, and friction factor of the pin-fi nned channel are included. It is found that an increase of the target surface curvature has signifi cant effects on the flow structure and thus the heat transfer on the target surface is augmented. The Taylor-Görtler vortices near the pin fins are also influenced by the target surface curvature. On the other hand, the nozzle-to-target surface distance influences the jet impingement and the vortices, which are generated by the curvature, remarkably. It is found that the area goodness factor and volume goodness factor are improved by the surface curvature.
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| 2. |
- Andersson, Martin N, et al.
(författare)
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A sex pheromone receptor in the Hessian fly Mayetiola destructor (Diptera, Cecidomyiidae)
- 2016
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Ingår i: Frontiers in Cellular Neuroscience. - : Frontiers Media SA. - 1662-5102. ; 10:SEP2016
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Tidskriftsartikel (refereegranskat)abstract
- The Hessian fly, Mayetiola destructor Say (Diptera, Cecidomyiidae), is a pest of wheat and belongs to a group of gall-inducing herbivores. This species has a unique life history and several ecological features that differentiate it from other Diptera such as Drosophila melanogaster and blood-feeding mosquitoes. These features include a short, non-feeding adult life stage (1–2 days) and the use of a long-range sex pheromone produced and released by adult females. Sex pheromones are detected by members of the odorant receptor (OR) family within the Lepidoptera, but no receptors for similar long-range sex pheromones have been characterized from the Diptera. Previously, 122 OR genes have been annotated from the Hessian fly genome, with many of them showing sex-biased expression in the antennae. Here we have expressed, in HEK293 cells, five MdesORs that display male-biased expression in antennae, and we have identified MdesOR115 as a Hessian fly sex pheromone receptor. MdesOR115 responds primarily to the sex pheromone component (2S,8E,10E)-8,10-tridecadien-2-yl acetate, and secondarily to the corresponding Z,E-isomer. Certain sensory neuron membrane proteins (i.e., SNMP1) are important for responses of pheromone receptors in flies and moths. The Hessian fly genome is unusual in that it encodes six SNMP1 paralogs, of which five are expressed in antennae. We co-expressed each of the five antennal SNMP1 paralogs together with each of the five candidate sex pheromone receptors from the Hessian fly and found that they do not influence the response of MdesOR115, nor do they confer responsiveness in any of the non-responsive ORs to any of the sex pheromone components identified to date in the Hessian fly. Using Western blots, we detected protein expression of MdesOrco, all MdesSNMPs, and all MdesORs except for MdesOR113, potentially explaining the lack of response from this OR. In conclusion, we report the first functional characterization of an OR from the Cecidomyiidae, extending the role of ORs as long-range sex pheromone detectors from the Lepidoptera into the Diptera.
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| 3. |
- Luo, Lei, et al.
(författare)
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Surface temperature reduction by using dimples/protrusions in a realistic turbine blade trailing edge
- 2018
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Ingår i: Numerical Heat Transfer; Part A: Applications. - : Informa UK Limited. - 1040-7782 .- 1521-0634. ; 74:5, s. 1265-1283
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Tidskriftsartikel (refereegranskat)abstract
- In this article, numerical simulations have been conducted on the heat transfer effect of dimple/protrusion layouts of a pin-finned wedge duct. Conjugate heat transfer calculations are further performed to investigate the cooling effect of modified schemes with dimples and protrusions added. Comparisons are carried out with a turbine second stage guide vane employed as the prototype. The dimple/protrusion-pin fin arrangement is set as the optimum one obtained above, and dimple depth/protrusion height varies from 0.2 to 0.3 times the structure diameter. It is found that the side-by-side arrangement and protrusion structure is more beneficial for the wedge duct endwall heat transfer. Comparison with the prototype blade shows that the addition of both dimples and protrusions are helpful in enhancing the trailing edge cooling effect. The cooling effect is increased with an increase in dimple depth/protrusion height. The results also show that the modified blade with protrusions attached at 0.3 height saves 0.48 g/s cooling mass flow and reaches the most positive performance with a 17 K, 14 K average temperature reduction, 0.022, 0.018 cooling effect increasing for pressure, suction side, respectively.
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| 4. |
- Qiu, Dandan, et al.
(författare)
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Analysis of heat transfer and fluid flow of a slot jet impinging on a confined concave surface with various curvature and small jet to target spacing
- 2019
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Ingår i: International Journal of Numerical Methods for Heat and Fluid Flow. - 0961-5539. ; 29:8, s. 2885-2910
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: This study aims to focus on the surface curvature, jet to target spacing and jet Reynolds number effects on the heat transfer and fluid flow characteristics of a slot jet impinging on a confined concave target surface at constant jet to target spacing. Design/methodology/approach: Numerical simulations are used in this research. Jet to target spacing, H/B is varying from 1.0 to 2.2, B is the slot width. The jet Reynolds number, Rej, varies from 8,000 to 40,000, and the surface curvature, R2/B, varies from 4 to 20. Results of the target surface heat transfer, flow parameters and fluid flow in the concave channel are performed. Findings: It is found that an obvious backflow occurs near the upper wall. Both the local and averaged Nusselt numbers considered in the defined region respond positively to the Rej. The surface curvature plays a positive role in increasing the averaged Nusselt number for smaller surface curvature (4-15) but affects little as the surface curvature is large enough (> 15). The thermal performance is larger for smaller surface curvature and changes little as the surface curvature is larger than 15. The jet to target spacing shows a negative effect in heat transfer enhancement and thermal performance. Originality/value: The surface curvature effects are conducted by verifying the concave surface with constant jet size. The flow characteristics are first obtained for the confined impingement cases. Then confined and unconfined slot jet impingements are compared. An ineffective point for surface curvature effects on heat transfer and thermal performance is obtained.
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| 5. |
- Sun, Liang, et al.
(författare)
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The mouthparts enriched odorant binding protein 11 of the Alfalfa Plant Bug Adelphocoris lineolatus displays a preferential binding behavior to host plant secondary metabolites
- 2016
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Ingår i: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 7, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Odorant binding proteins (OBPs) are proposed to be directly required for odorant discrimination and represent potential interesting targets for pest control. In the notoriously agricultural pest Adelphocoris lineolatus, our previous functional investigation of highly expressed antennal OBPs clearly supported this viewpoint, whereas the findings of the current study by characterizing of AlinOBP11 rather indicated that OBP in hemipterous plant bugs might fulfill a different and tantalizing physiological role. The phylogenetic analysis uncovered that AlinOBP11 together with several homologous bug OBP proteins are potential orthologs, implying they could exhibit a conserved function. Next, the results of expression profiles solidly showed that AlinOBP11 was predominantly expressed at adult mouthparts, the most important gustatory organ of Hemiptera mirid bug. Finally, a rigorously selective binding profile was observed in the fluorescence competitive binding assay, in which recombinant AlinOBP11 displayed much stronger binding abilities to non-volatile secondary metabolite compounds than the volatile odorants. These results reflect that AlinOBP11, even its orthologous proteins across bug species, could be associated with a distinctively conserved physiological role such as a crucial carrier for non-volatiles host secondary metabolites in gustatory system.
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