INCAS SUBSONIC WIND TUNNEL

The INCAS Subsonic Wind Tunnel is a closed circuit, continuous, atmospheric pressure facility with a maximum speed of 110 m/s. The test section is octagonal ,of 2.5 m wide, 2.0 m high and 4 m long. The tunnel is powered by a 1200 kW, air cooled variable speed DC motor which drives a 12 blade, 3.5 m diameter fan and is equipped with a six component pyramidal type external mechanical balance with a 700 Kgf maximum lift capacity.The angle of attack range is between -45º and +45º while the yaw angle range is between -140º and +216º .The data acquisition system has been modified recently to allow the recording of all test data on a PC - type computer using LABVIEW and a PXI – type chassis containing specialized data acquisition modules.The tunnel is equipped with a variable frequency electrical supply system for powered models and a 10 bar compressed air supply for pneumatic flow control applications.In the recent years the subsonic wind tunnel has been intensively used for tests within several European projects (AVERT, CESAR and others)

Experimental analysis for aerodynamic drag of the electric locomotives

The purpose of this paper is to make a comparative analysis on the influence of the aerodynamic drag, in case of the electric rail vehicles for a series of situations encountered in exploitation. The article presents experimental results obtained following a geometric modelling at scale 1: 12, on a modular model for the electric locomotives LE 060EA 5100kW and LE-MA 060 TransMontana 6000kW. Tests were made at INCAS (National Institute for Aerospace Research “ElieCarafoli”) in the subsonic wind tunnel

Wind Tunnel Testing of Passive High-Lift Systems

This paper presents experimental results obtained with passive high lift systems using a combination of smart flap kinematics and vortex generators. A mid-scale 2.5D wind tunnel model based on DLR-F15 is tested in INCAS Subsonic Wind Tunnel, swept at 30 deg, incorporating the slat, 54 flap/VG/chord extension configurations and test matrix, developed by Dassault-Aviation. INCAS designed, manufactured and instrumented components to be added to the existing INCAS-F15 2D wind tunnel model. The test campaign was completed and results are presented

STATE OF THE ART TECHNIQUES USED FOR NOISE SOURCE IDENTIFICATION ON COMPLEX BODIES

Over the last few decades, many approaches have been undertaken in order to asses detailed noise source identification on complex bodies, i.e. aircrafts, cars, machinery. Noise source identification implies to accurately obtain the position and frequency of the dominant noise sources. There are cases where traditional testing methods can not be applied at all or their use involves some limitations. Optical systems used for near field analysis require a line of sight that may not be available. The state-of-the-art technology for this purpose is the use of a large number of microphones whose signals are acquired simultaneously, i.e. microphone phased array. Due to the excessive cost of the instruments and the data acquisition system required, the implementation of this technology was restricted to governmental agencies (NASA, DLR) and big companies such as Boeing and Airbus. During the past years, this technique was developed in wind tunnels and some universities to perform noise source identification on scale airframes, main landing gear models, and aerodynamic profiles (used on airplanes, helicopter rotors and wind mills)

Percutaneous Chevron Osteotomy: A Prospective Randomized Controlled Trial

Introduction: Minimally invasive surgical techniques for hallux valgus have gained popularity, showing good results characterized by smaller postoperative scars, less pain, lower infection risk, and fewer wound complications. Given the lack of evidence available in our country regarding this subject, especially about this type of surgical technique, our paper aims to compare open and MIS approaches for chevron osteotomy. We evaluated the outcome and complications after 12 months. Materials and Methods: We undertook a prospective, randomized, controlled, single-center study between October 2017 and December 2020. The patients were randomized into two groups: one group that received percutaneous chevron osteotomy (MIS), and the other, open chevron osteotomy (OC). For clinical assessment, we determined the function and the level of pain using the Visual Analogue Scale (VAS) and The American Orthopaedic Foot and Ankle Surgery score (AOFAS). The VAS scale was measured before the surgical procedure, at discharge, and at 3 weeks, 6 weeks, 6 months, and 12 months after surgery. The AOFAS score was calculated preoperatively and after 6 months. The hallux angle (HVA) and intramedullary angle (IMA) were measured preoperatively, and at 6 weeks, 6 months and 12 months. Results: We included 26 cases in the open chevron osteotomy group (24 female, 2 male) and 24 in the MIS group (24 female, 0 male). Both groups demonstrated improvements regarding the IMA and HVA at the last follow-up without any significant differences between the groups at the final assessment. The VAS showed significantly better post-operative results for the MIS group at discharge (p p p p = 0.004) post-surgery. The AOFAS showed no significant differences either before or after surgery. Four cases with screw prominence were reported, three of which belonged to the MIS group. Only one case with metatarsalgia was found in the OC group. Conclusions: This paper demonstrates that minimally invasive chevron osteotomy has comparable results with open chevron osteotomy, even though surgical time and radiological exposure are significantly longer. More studies are required to evaluate the complications and the risk of recurrences

Some Theoretical and Experimental Evidence for Particularities of the Siloxane Bond

The specific features of the siloxane bond unify the compounds based on it into a class with its own chemistry and unique combinations of chemical and physical properties. An illustration of their chemical peculiarity is the behavior of 1,3-bis(2-aminoethylaminomethyl)tetramethyldisiloxane (AEAMDS) in the reaction with carbonyl compounds and metal salts, by which we obtain the metal complexes of the corresponding Schiff bases formed in situ. Depending on the reaction conditions, the fragmentation of this compound takes place at the siloxane bond, but, in most cases, it is in the organic moieties in the β position with respect to the silicon atom. The main compounds that were formed based on the moieties resulting from the splitting of this diamine were isolated and characterized from a structural point of view. Depending on the presence or not of the metal salt in the reaction mixture, these are metal complexes with organic ligands (either dangling or not dangling silanol tails), or organic compounds. Through theoretical calculations, electrons that appear in the structure of the siloxane bond in different contexts and that lead to such fragmentations have been assessed

When Critical View of Safety Fails: A Practical Perspective on Difficult Laparoscopic Cholecystectomy

The incidence of common bile duct injuries following laparoscopic cholecystectomy (LC) remains three times higher than that following open surgery despite numerous attempts to decrease intraoperative incidents by employing better training, superior surgical instruments, imaging techniques, or strategic concepts. This paper is a narrative review which discusses from a contextual point of view the need to standardise the surgical approach in difficult laparoscopic cholecystectomies, the main strategic operative concepts and techniques, complementary visualisation aids for the delineation of anatomical landmarks, and the importance of cognitive maps and algorithms in performing safer LC. Extensive research was carried out in the PubMed, Web of Science, and Elsevier databases using the terms ”difficult cholecystectomy”, ”bile duct injuries”, ”safe cholecystectomy”, and ”laparoscopy in acute cholecystitis”. The key content and findings of this research suggest there is high intersocietal variation in approaching and performing LC, in the use of visualisation aids, and in the application of safety concepts. Limited papers offer guidelines based on robust data and a timid recognition of the human factors and ergonomic concepts in improving the outcomes associated with difficult cholecystectomies. This paper highlights the most relevant recommendations for dealing with difficult laparoscopic cholecystectomies