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American Society for Testing and Materials

The boundary layer equations for plane, incompressible, and steady flow are 

$$\matrix{ {u{{\partial u} \over {\partial x}} + v{{\partial u} \over {\partial y}} = - {1 \over \varrho }{{\partial p} \over {\partial x}} + v{{{\partial ^2}u} \over {\partial {y^2}}},} \cr {0 = {{\partial p} \over {\partial y}},} \cr {{{\partial u} \over {\partial x}} + {{\partial v} \over {\partial y}} = 0.} \cr }$$

Boundary Layer Theory

Boundary-layer flow of a nanofluid past a stretching sheet

The flow of homogeneous fluids through porous media: analogies with other physical problems

Natural convective boundary-layer flow of a nanofluid past a vertical plate

Due to its simplicity, the valveless pulsejet may be an ideal low -cost micro -propulsion system. Although a considerable amount of work has been done on developi ng different types of valveless pulsejet s, understanding of the operation of these jets is still very limited. In this paper, computational methods are used to investigate how modification of the inlet size and placing an obstruction in the combustion cham ber affect the overall performance of a valveless pulsejet in both a static and convective free stream . Different inlet lengths and diameters are simulated to optimize the geometry to yield largest net thrust. A 0.12 volume ratio between the inlet and comb ustion chamber is shown to be the best for a static pulsejet. However, this ratio must be decreased as the free stream velocity increases to account for ram compression. Different interior obstructions are also placed in the combustion chamber to modify th e flow pattern and increase thrust. Results indicate that a properly placed obstruction in the pulsejet can significantly improve its performance.

Numerical study of t he effect of inlet s ize and interior obstructions on the performance of valve less pulsejets

This paper investigates numerically heat transfer in a helical pipe filled with a fluid saturated porous medium. The analysis is based on the full momentum equation for porous media that accounts for the Brinkman and Forchheimer extensions of the Darcy law as well as for the flow inertia. Numerical computations are performed in an orthogonal helical coordinate system. The effects of the Darcy number, the Forchheimer coefficient as well as the Dean and Germano numbers on the axial flow velocity, secondary flow, temperature distribution, and the Nusselt number are analyzed.Copyright © 2005 by ASME

Numerical Investigation of Heat Transfer in Forced Convection in a Helical Pipe Filled With a Porous Medium

Neuron response to injury depends on the distance to the lesion site, which means that neurons are capable of sensing this distance. Several mechanisms explaining how neurons can do this have been proposed and it is possible that neurons use a combination of several mechanisms to make such measurements. In this paper we investigate the feasibility of the simplest mechanism, which is based on the hypothesis that death signals, produced at the lesion site, propagate toward the neuron soma. The signals are propelled by dynein motors. If signals have a finite half-life, they decay as they propagate. By measuring the concentration of death signals arriving to the soma, neurons should thus be able to determine the distance to the injury site. We develop and solve a transport equation based on the above model. We investigate how a death signal distribution depends on the dynein velocity distribution. We evaluate the efficiency of such a mechanism by investigating the sensitivity of death signal concentration at the soma to the distance to the injury site. By using the hypothesis that system performance is optimized by evolution, we evaluate death signal half-lives that would maximize this sensitivity.

Can a death signal half-life be used to sense the distance to a lesion site in axons?

The objective of this paper is to discuss the theory of free surface flows with solidification. This type of open-channel flows is relevant to a number of important manufacturing processes, such as the horizontal continuous casting of carbon steel. Since carbon steel is a binary alloy, in formulating a mathematical model in addition to accounting for fluid flow and heat transfer, it is also necessary to account for the solute transport and for the two-phase region (the mushy zone) effects. Difficulties of the theory are discussed. 

Heat and mass transfer in free surface flows with solidification

In this chapter, we discuss the mathematical modeling of convection in 
nanofluids, with emphasis on two problems that are paradigmatic for confined convection and external convection, respectively. The first problem 
is the onset of convection in a fluid layer heated uniformly from below and 
the second problem involves a thermal boundary layer adjacent to a vertical wall. We also consider forced convection in a channel.

Andrey V. Kuznetsov

Papers

Numerical study of t he effect of inlet s ize and interior obstructions on the performance of valve less pulsejets

Numerical Investigation of Heat Transfer in Forced Convection in a Helical Pipe Filled With a Porous Medium

Can a death signal half-life be used to sense the distance to a lesion site in axons?

Heat and mass transfer in free surface flows with solidification

◾ Modeling Convection in Nanofluids: From Clear Fluids to Porous Media