Aleksandrs Urbahs, Margarita Urbaha and Kristīne Carjova
The aim of this research is to develop a vertical rotation axis variable geometry wind turbine (WT). The experimental prototype is being manufactured with the help of CAM (Computer-aided manufacturing) technologies – computer-based preparation of the product manufacturing process. The Institute of Aeronautics of Riga Technical University is using CNC (Computer Numerical Control) machines for manufacturing the innovative WT and its components. The aerodynamic research has been done in T-4 wind tunnel at an air flow rate from 5 m/s to 30 m/s. The power increase of the variable geometry WT is a topical issue. Installation of such WTs in wind farms is possible and is subject to further research.
Aleksandrs Urbahs, Sudip Das, Shravan Koundinya Vutukuru and Kristīne Carjova
Experiments and computational studies were carried out to get an understanding of the flow field around a rectangular supersonic intake with pointed cowl shape. Experiments include quantitative pressure measurements and flow visualization studies by using schlieren techniques. The effects of the presence of various cowl shapes on ramp surface have been obtained computationally at Mach 2.0. The experiments were carried out only for the pointed cowl. Schlieren Photographs were taken. Three-Dimensional simulations were made by using FLUENT at supersonic speed. The details of the experiments and computations are discussed.
Aleksandrs Urbahs, Konstantīns Savkovs, Gints Rijkuris and Darja Andrejeva
Corrosion is one of the most common naturally occurring processes studied by thermodynamics, which includes oxidation process, metal disruption, and its chemical and electrochemical effects under environmental influence. Corrosion of metal and equipment accounts for a considerable proportion of total corrosion losses, thus providing the impetus for further investigation and developments related to corrosion protection in order to provide transport systems and industry with corrosion preventive materials and tools.
Aleksandrs Urbahs, Kristīne Carjova, Aleksejs Nasibullins and Dmitry Nedelko
The paper contains results of experimental research carried out helicopter bench. In order to create an attenuation chart for AE signal amplitude in helicopter fuselage, a number of experiments were performed on the frame and stringers, inside the fuselage. Later helicopter test bench was used to develop defect localization methodology of helicopter structure fatigue damage technical diagnostics. Analysing helicopter structural defects for different helicopters types it is concluded that the joint elements of helicopter tail boom are still exposed to fatigue crack formation. AE method shows highly effective results predicting fracture of helicopter joint elements.
Aleksandrs Urbahs, Jurate Suziedelyte Visockiene, Yen-Chen Liu, Kristīne Carjova and Sergey Kravchenko
Paper is related to development of flying robot system. The main objective is to mingle the professional backgrounds in three research directions: development of the aerial vehicle and localization, development of the tele-interaction framework and control system, development of the image fusion system and photogrammetry. Block diagrams give brief description of the systems and sub-systems under the proposed environmental system. Structure of the monitoring UAV adapted for the hand launch given.
Aleksandrs Urbahs, Rima Mickevičienė, Vasilij Djačkov, Kristīne Carjova, Valdas Jankūnas, Mindaugas Zakarauskas, Natalia Panova and Dita Lasmane
The paper gives brief description of the conventional and innovative hydrography survey methods and constraints connected with the realization. Proposed hydrographic survey system based on the use of Unmanned Aerial and Maritime systems provides functionality to conduct hydrographic measurements and environment monitoring. System can be easily adapted to fulfil marine safety and security operations, e.g. intrusion threat monitoring, hazardous pollutions monitoring and prevention operations, icing conditions monitoring.