In this paper a new process is presented for improving efficiency of cyclone de-dusting systems. The cyclone is coupled with a specially designed cylindrical chamber which includes a rotating tube inside it with air impinging nuzzles, drilled on the peripheral surface of the tube. The nuzzles help in pushing and throwing the particles to the outer radius distances during downward flow of du...

This report summarizes modeling studies supporting the second phase of quarter-scale testing for the NTSB investigation of the TWA Flight 800 accident. In this study, fuel-air tests were conducted to replicate earlier tests to assure repeatability of results. The quarter-scale test tank was redesigned to use heated Jet-A fuel/air mixtures at reduced ambient pressures. Although violent combustio...

A new type of pulsed water jet, which uses principles of self-resonance to create pressure fluctuations, is now being developed. The advantages of pulsing to improve the erosive action of a jet—by interrupting the flow, hence using the water hammer impact stress created by each individual slug—have long been appreciated by the users of water jets for cutting and cleaning applications. Of severa...

Water solutions with electrical conductivities ranging from that of the deionized water up to 2 S/m have been electrosprayed in air through narrow silica tubes. Results show unambiguously that steady cone jets of water in air without the assistance of glow discharge can be formed for the range of electrical conductivities we have explored. The absence of corona discharge has been proven not onl...

A variety of different types of actuators have been previously investigated as flow control devices. Potential applications include the control of boundary layer separation in external flows, as well as jet engine inlet and diffuser flow control. The operating principles for such devices are typically based on either mechanical deflection of control surfaces (which include MEMS flap devices), m...

Dielectric-barrier-discharge (DBD) plasma actuators are all-electric devices with no moving parts. They are made of a simple construction, consisting only of a pair of electrodes sandwiching a dielectric sheet. When AC voltage is applied, air surrounding the upper electrode is ionized, which is attracted towards the charged dielectric surface to form a wall jet. Control of flow over land and ai...

This paper describes the use of air-coupled ultrasonic tomography for the simultaneous measurement of flow and temperature variations in gases. Air-coupled ultrasonic transducers were used to collect through-transmission data from a heated gas jet. A transducer pair was scanned in two-dimensional sections at an angle to the jet, and travel time and amplitude data recorded along various paths in...

Indoor air distribution has great impact on people’s thermal sensation. Therefore, how to remove the indoor excess heat becomes an important issue to create a thermally comfortable indoor environment. To expel the extra indoor heat effectively, this paper used a dynamic CFD approach to study the effect of an air-supply guide vane swinging periodically on the indoor air distribution within a mod...

In the last decades, Synthetic jet actuators have gained much interest among the flow control techniques due to their short response time, high jet velocity and absence of traditional piping, which matches the requirements of reduced size and low weight. A synthetic jet is generated by the diaphragm oscillation (generally driven by a piezoelectric element) in a relatively small cavity, producin...