Comparison of boiler feed pumps for cesium and potassium Rankine cycle systems

Comparison of electromagnetic and centrifugal pumps for cesium and potassium Rankine cycle system

Propagating plane harmonic waves through finite length plates of variable thickness using finite element techniques

An analysis is given using finite element techniques which addresses the propagaton of a uniform incident pressure wave through a finite diameter axisymmetric tapered plate immersed in a fluid. The approach utilized in developing a finite element solution to this problem is based upon a technique for axisymmetric fluid structure interaction problems. The problem addressed is that of a 10 inch diameter axisymmetric fixed plate totally immersed in a fluid. The plate increases in thickness from approximately 0.01 inches thick at the center to 0.421 inches thick at a radius of 5 inches. Against each face of the tapered plate a cylindrical fluid volume was represented extending five wavelengths off the plate in the axial direction. The outer boundary of the fluid and plate regions were represented as a rigid encasement cylinder as was nearly the case in the physical problem. The primary objective of the analysis is to determine the form of the transmitted pressure distribution on the downstream side of the plate

Building up a dairy herd in Kansas

Citation: Clark, C. H. Building up a dairy herd in Kansas. Senior thesis, Kansas State Agricultural College, 1902.Morse Department of Special CollectionsIntroduction: When we review the dairy interests of Kansas, noting the improved methods of the cheese factory, the skimming station and the creamery, and the increasing demand for milk in our cities, we turn naturally to the source of the raw material and inquire as to its permanence and whether it is equal to the demands made upon it. We all know that the cow, as a source of milk supply to the human race, is something of an abnormal creature, made possible only by a long and careful process of feeding, breeding, selection and milking, and that without due precautions she will gradually drift back to the natural conditions of giving only milk enough to supply the needs of her offspring. The possibility of not only maintaining the present high standard, but of further, and more rapid and wide spread improvement is clearly shown when we consider what has already been done under conditions less favorable than now exist. The Holstein-Friesian, Jersey, Guernsey and Ayrshire herds have become famous as milk producers, though many of the breeders of these cattle know little or nothing of the foundation principles of breeding, feeding and variation. They lacked the stimulus that has been given by the Babcock test and the invention of modern dairy machinery and methods. Knowledge was not so easily obtained as at present. There was no improved stock with which the early breeders could cross their common stock, for all cattle were wild originally. The dawn of the twentieth century certainly offers great encouragement to those who wish to continue the work so well begun

Evaluation of subgrid-scale turbulence models using a fully simulated turbulent flow

An exact turbulent flow field was calculated on a three-dimensional grid with 64 points on a side. The flow simulates grid-generated turbulence from wind tunnel experiments. In this simulation, the grid spacing is small enough to include essentially all of the viscous energy dissipation, and the box is large enough to contain the largest eddy in the flow. The method is limited to low-turbulence Reynolds numbers, in our case R sub lambda = 36.6. To complete the calculation using a reasonable amount of computer time with reasonable accuracy, a third-order time-integration scheme was developed which runs at about the same speed as a simple first-order scheme. It obtains this accuracy by saving the velocity field and its first-time derivative at each time step. Fourth-order accurate space-differencing is used

Effect of polarization on superfluidity in low density neutron matter

It is shown that, contrary to an earlier estimate, the polarizability of the neutron medium tends to suppress rather than enhance the isotropic energy gap in low-density neutron-star matter

Using CO line ratios to trace the physical properties of molecular clouds

The carbon monoxide (CO) rotational transition lines are the most common tracers of molecular gas within giant molecular clouds (MCs). We study the ratio ($R_{2-1/1-0}$) between CO's first two emission lines and examine what information it provides about the physical properties of the cloud. To study $R_{2-1/1-0}$ we perform smooth particle hydrodynamic simulations with time dependent chemistry (using GADGET-2), along with post-process radiative transfer calculations on an adaptive grid (using RADMC-3D) to create synthetic emission maps of a MC. $R_{2-1/1-0}$ has a bimodal distribution that is a consequence of the excitation properties of each line, given that $J=1$ reaches local thermal equilibrium (LTE) while $J=2$ is still sub-thermally excited in the considered clouds. The bimodality of $R_{2-1/1-0}$ serves as a tracer of the physical properties of different regions of the cloud and it helps constrain local temperatures, densities and opacities. Additionally this bimodal structure shows an important portion of the CO emission comes from diffuse regions of the cloud, suggesting that the commonly used conversion factor of $R_{2-1/1-0}\sim 0.7$ between both lines may need to be studied further.Comment: 10 pages, 8 figures, accepted to MNRA

Acoustic modes in fluid networks

Pressure and flow rate eigenvalue problems for one-dimensional flow of a fluid in a network of pipes are derived from the familiar transmission line equations. These equations are linearized by assuming small velocity and pressure oscillations about mean flow conditions. It is shown that the flow rate eigenvalues are the same as the pressure eigenvalues and the relationship between line pressure modes and flow rate modes is established. A volume at the end of each branch is employed which allows any combination of boundary conditions, from open to closed, to be used. The Jacobi iterative method is used to compute undamped natural frequencies and associated pressure/flow modes. Several numerical examples are presented which include acoustic modes for the Helium Supply System of the Space Shuttle Orbiter Main Propulsion System. It should be noted that the method presented herein can be applied to any one-dimensional acoustic system involving an arbitrary number of branches