1,725,404 research outputs found
Computational and experimental study on the aerodynamic performance of NACA 4412 airfoil with slot and groove
No full textSince the Wright Brothers’ first flight in 1903, extensive research has been dedicated to improving the aerodynamic performance of aircraft. This study investigates the effect of two distinct wing geometric modifications on airfoil performance at high angles of attack (AOAs). These two modifications are slot, specifically the NACA 4412 with only a slot, and groove, specifically the NACA 4412 with both a slot and a groove. The investigation combines numerical simulation using ANSYS fluent with experimental evaluations conducted in the VDAS AF1300 subsonic wind tunnel. Since turbulent airflow often results in early stall, the primary objective of this research is to delay the stall angle of the normal NACA 4412 airfoil by mitigating local separation zones, and boundary layer transitions. Numerical simulations are performed at airspeeds of 20 m/s and 43.9 m/s, while experimental investigations are conducted at a speed of 20 m/s. The results indicate that both modified airfoils have higher lift-to-drag ratio than the normal airfoil at high AOAs. Specifically, the NACA 4412 airfoil with only a slot demonstrates the highest lift-to-drag ratio among the modified airfoils at high AOAs. Moreover, the NACA 4412 airfoil equipped with a slot and a groove demonstrates the highest stall angle, measured at 18°, compared to the normal NACA 4412 airfoil with a stall angle of 14°. At high AOA, the NACA 4412 airfoil with a slot generates a nearly 35 % higher lift coefficient than the normal NACA 4412 airfoil, while the NACA 4412 with a slot and a groove achieves almost a 16 % higher lift coefficient than the normal NACA 4412 airfoil
Block Card 4412 Willis Boulevard
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Ranch houses | 4412 Willis Boulevard (Toledo, Ohio) | Dwelling | Willis Place (Toledo, Ohio) | Franklin Park Area (Toledo, Ohio) | Trilby Area (Toledo, Ohio)
Block Card 4412 Clarewood Drive
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: dwelling | 4412 Clarewood Drive (Toledo, Ohio) | Ranch houses | Franklin Park Area (Toledo, Ohio) | West Toledo (Toledo, Ohio
Effect Of Vibration Frequency On Naca 4412 Airfoil Aerodynamic Performance
No full textVibration is due to the aeroelastic stability of a typical section airplane wing NACA 4412 which finishes in general by the breaking of the plane, it can be determined as a dynamic instability of the structure. As vibration might lead to catastrophe, it is very important to understand the effect of vibration frequency on an airfoil aerodynamic performance. Thus, this project was designed to obtain the aerodynamic characteristics on NACA 4412 airfoil at different vibration frequencies and to study the aerodynamic characteristics on NACA 4412 airfoil at different Reynolds numbers. The experiment was conducted at two different cases, one by using a rigid airfoil without vibration motor attached on it while another case is by using a vibrating airfoil. As known, the performance of an aircraft wing depends mostly on the aerodynamic characteristics such as the lift force, drag force and etc. In this paper, experiment will be conducted in turbulent flow with Reynolds numbers (17 000, 27 000, 34 000, 46 000 and 57 000) at different angles of attack (0°, 10°, 20°, and 30°) for the two cases mentioned. For the case of using vibration motor, the vibration frequency applied to the airfoil model is varied by the number of rotation of the vibration motor used to the induce vibration. The results will be recorded and plotted to observe how the lift-to-drag ratio of the NACA 4412 airfoil model vary with different vibration frequencies. The effect of varying Reynolds numbers on the aerodynamic characteristics was also investigated in both cases
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Linked collectors and determiners for: Revision of Stenetra Masi, 1931 (Hymenoptera: Chalcidoidea: Pteromalidae).
No full textNatural history specimen data linked to collectors and determiners held within, "Revision of Stenetra Masi, 1931 (Hymenoptera: Chalcidoidea: Pteromalidae)". Claims or attributions were made on Bionomia by volunteer Scribes, <a href="http://bionomia.net/dataset/819b234f-6385-4412-a51b-d7a82f490ac4">https://bionomia.net/dataset/819b234f-6385-4412-a51b-d7a82f490ac4</a> using specimen data from the dataset aggregated by the Global Biodiversity Information Facility, <a href="https://gbif.org/dataset/819b234f-6385-4412-a51b-d7a82f490ac4">https://gbif.org/dataset/819b234f-6385-4412-a51b-d7a82f490ac4</a>. Formatted as a Frictionless Data package
Linked collectors and determiners for: SDSU - San Diego State University Herbarium.
No full textNatural history specimen data linked to collectors and determiners held within, "SDSU - San Diego State University Herbarium". Claims or attributions were made on Bionomia by volunteer Scribes, <a href="http://bionomia.net/dataset/44525bc9-4412-441a-9890-1df3d289e3f6">https://bionomia.net/dataset/44525bc9-4412-441a-9890-1df3d289e3f6</a> using specimen data from the dataset aggregated by the Global Biodiversity Information Facility, <a href="https://gbif.org/dataset/44525bc9-4412-441a-9890-1df3d289e3f6">https://gbif.org/dataset/44525bc9-4412-441a-9890-1df3d289e3f6</a>. Formatted as a Frictionless Data package
Linked collectors and determiners for: Institut Botanic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), BC-Lichen-Werner.
No full textNatural history specimen data linked to collectors and determiners held within, "Institut Botanic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), BC-Lichen-Werner". Claims or attributions were made on Bionomia by volunteer Scribes, <a href="http://bionomia.net/dataset/f534f8bf-b84c-4412-bfee-536c000528c6">https://bionomia.net/dataset/f534f8bf-b84c-4412-bfee-536c000528c6</a> using specimen data from the dataset aggregated by the Global Biodiversity Information Facility, <a href="https://gbif.org/dataset/f534f8bf-b84c-4412-bfee-536c000528c6">https://gbif.org/dataset/f534f8bf-b84c-4412-bfee-536c000528c6</a>. Formatted as a Frictionless Data package
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