A study of the mechanisms of cracking-induced mistuning in bladed disks is presented in this paper. An analytical model for a bladed disk was formulated using lumped-mass-beams, and a cracked blade was represented by a beam with a through-crack at the root. Local stiffness reduction due to cracking was incorporated using a flexibility matrix method. The dynamic characteristics of the bladed dis...

Turbine machinery has an extraordinary wide range of applications in the aviation, aerospace, automotive, energy and many other industries. The turbine blade is one of the most important parts of turbine machinery, and the characteristic parameters, pressure ratio of the engine and rotating speed of the turbine are all related to the shape and size of blades. Therefore, the profile measurement ...

The control strategies of blade loads are proposed for the characteristics of blade stresses of variable-speed variablepitch wind turbine. Blade loads are divided into two static and dynamic components. The pitch angle and generator torque are controlled by Single neuron PID controller in the static part. Variables are converted from rotational coordinate to fixed coordinate through multi-blade...

Tip vortex cavitation is one of well known patterns of cavitation phenomenon which occurs in axial pumps. This pattern of cavitation occurs due to pressure difference between the pressure and suction sides of blades of an axial pump. Since the pressure in the pressure side of the blade is higher than the pressure in its suction side, thus a very small portion of liquid flow flows back from pres...

PURPOSE It is generally accepted that using a video laryngoscope is associated with an improved visualization of the glottis. However, correctly placing the endotracheal tube might be challenging. Channeled video laryngoscopic blades have an endotracheal tube already pre-loaded, allowing to advance the tube once the glottis is visualized. We hypothesized that use of a channel blade with pre-loa...

The structural properties of Higher harmonic Aeroacoustic Rotor Test (HART I) blades have been measured using the original set of blades tested in the wind tunnel in 1994. A comprehensive rotor dynamics analysis is performed to address the effect of the measured blade properties on airloads, blade motions, and structural loads of the rotor. The measurements include bending and torsion stiffness...

The study of vibration response of a turbine blade helps to detect the crack presence in the blade which alters its dynamic characteristics. The change is characterized by changes in the modal parameters associated with natural frequencies. In this paper, study of vibration response is made for turbine blade in the presence of a crack like defect. Turbine blade is initially assumed as a cantile...

the brønsted acidic ionic liquid ([bmim]hso4) catalyzed three-component synthesis of 2h-indazolo[2,1-b]phthalazine-trione derivatives at room temperature. the integrity of the ionic liquid remains reasonably unchanged when it is separated from the reaction mixture by water extraction, as it can be recycled several times without any loss of activity in each of the title syntheses. the products a...

dodecylbenzenesulfonic acid (dbsa) was used as an efficient, cheap and stable brønsted catalyst for acetylation of alcohols and phenols and formylation of alcohols under solvent-free conditions. various primary, secondary and tertiary alcohols were acetylated with acetic anhydride as an acetylating agent under solvent-free conditions in the presence of catalytic amount of dbsa at room temperatu...

During the course of our work on leishmaniasis in the Amazon Region, we have felt the need for a practical instrument for collecting and manipulating lymph samples from skin and mucosal lesions in human subjects. Existing methods for obtaining biopsy material or exudates include the use of scalpel blades, disposable stylets, wooden toothpicks, dermatological punches and aspiration with or witho...