D Nosenchuck - Academia.edu (original) (raw)
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Papers by D Nosenchuck
Journal of Fluid Mechanics, 1982
A new technique using surface-film activators has been developed to induce and control laminar-in... more A new technique using surface-film activators has been developed to induce and control laminar-instability waves by periodic heating. A flat plahe was instrumented and installed in the GALCIT High-speed Water Tunnel with flush-mounted surface heaters and probes. Extremely two-dimensional naturally occurring Tolmien-Schlichting (TS) waves were observed along with the subsequent formation of turbulent spots. Laminar-instability waves were then excited in a controlled fashion using the surface-mounted heaters. A preliminary experiment on cancellation of excited laminar-instability waves was carried out. Finally, turbulent spots were produced using amplitude-modulated bursts to form Gaussian TS wave packets. Flow visualization, along with wall shear measurements, was used to infer the velocity and vorticity field near the wall.
Journal of Experimental Marine Biology and Ecology, 1988
Abstract Cultures of the marine dinoflagellate Gonyaulax polyedra Stein were exposed to a variety... more Abstract Cultures of the marine dinoflagellate Gonyaulax polyedra Stein were exposed to a variety of flow regimes in small tubes, pressure chambers, and vessels in which objects could be rotated. Bioluminescence was mechanically stimulated by changes in shear, ...
Computers & Structures, 1988
There exists a wide range of problems in computational physics where no analytical and few experi... more There exists a wide range of problems in computational physics where no analytical and few experimental results exist. Of particular interest at the Navier-Stokes Supercomputer Laboratory of Princeton University is a range of problems dealing with fluid flow. Most flows of interest are complex in nature, involving non-simple boundaries and initial conditions. A typical case involves turbulent flow over arbitrary air and water vehicles, Of particular interest is the active control of these flows. To simulate such flows directly, with boundary and initial conditions directed towards active control schemes, one must numerically solve the Navier-Stokes equations of fluid motion. These equations form a set of nonlinear, coupled, partial differential equations that account for the conservation of mass, momentum and energy in continuum flow. Because of the vast amount of computer memory and associated processing speed required to tackle even simple numerical simulations, a typical general-purpose supercomputer (e.g. Cray-2) would require unreasonably large computer time to tackle most flows involving turbulence. To overcome this difficulty, a multipurpose parallel supercomputer has been designed and is being fabricated. Called the Navier-Stokes Computer (NSC), its primary function is the direct simulation of complex flows. The NSC is comprised of a multi-dimensional array of processing nodes with local memory. At 20 MHz, each node has a 640 MFLOP parallel-pipefiied recotigurabk arithmetic unit coupled to two Gbytes of local memory. Early hardware and software benchmarks indicate that a single node is roughly comparable to the measured performance of a Cray-2. An overview of the NSC architecture along with a discussion of a turbulence simulation of this architecture is presented.
Journal of Fluid Mechanics, 1982
Journal of Fluid Mechanics, 1982
A new technique using surface-film activators has been developed to induce and control laminar-in... more A new technique using surface-film activators has been developed to induce and control laminar-instability waves by periodic heating. A flat plahe was instrumented and installed in the GALCIT High-speed Water Tunnel with flush-mounted surface heaters and probes. Extremely two-dimensional naturally occurring Tolmien-Schlichting (TS) waves were observed along with the subsequent formation of turbulent spots. Laminar-instability waves were then excited in a controlled fashion using the surface-mounted heaters. A preliminary experiment on cancellation of excited laminar-instability waves was carried out. Finally, turbulent spots were produced using amplitude-modulated bursts to form Gaussian TS wave packets. Flow visualization, along with wall shear measurements, was used to infer the velocity and vorticity field near the wall.
Journal of Experimental Marine Biology and Ecology, 1988
Abstract Cultures of the marine dinoflagellate Gonyaulax polyedra Stein were exposed to a variety... more Abstract Cultures of the marine dinoflagellate Gonyaulax polyedra Stein were exposed to a variety of flow regimes in small tubes, pressure chambers, and vessels in which objects could be rotated. Bioluminescence was mechanically stimulated by changes in shear, ...
Computers & Structures, 1988
There exists a wide range of problems in computational physics where no analytical and few experi... more There exists a wide range of problems in computational physics where no analytical and few experimental results exist. Of particular interest at the Navier-Stokes Supercomputer Laboratory of Princeton University is a range of problems dealing with fluid flow. Most flows of interest are complex in nature, involving non-simple boundaries and initial conditions. A typical case involves turbulent flow over arbitrary air and water vehicles, Of particular interest is the active control of these flows. To simulate such flows directly, with boundary and initial conditions directed towards active control schemes, one must numerically solve the Navier-Stokes equations of fluid motion. These equations form a set of nonlinear, coupled, partial differential equations that account for the conservation of mass, momentum and energy in continuum flow. Because of the vast amount of computer memory and associated processing speed required to tackle even simple numerical simulations, a typical general-purpose supercomputer (e.g. Cray-2) would require unreasonably large computer time to tackle most flows involving turbulence. To overcome this difficulty, a multipurpose parallel supercomputer has been designed and is being fabricated. Called the Navier-Stokes Computer (NSC), its primary function is the direct simulation of complex flows. The NSC is comprised of a multi-dimensional array of processing nodes with local memory. At 20 MHz, each node has a 640 MFLOP parallel-pipefiied recotigurabk arithmetic unit coupled to two Gbytes of local memory. Early hardware and software benchmarks indicate that a single node is roughly comparable to the measured performance of a Cray-2. An overview of the NSC architecture along with a discussion of a turbulence simulation of this architecture is presented.
Journal of Fluid Mechanics, 1982