Three-dimensional turbopump flowfield analysis

A program was conducted to develop a flow prediction method applicable to rocket turbopumps. The complex nature of a flowfield in turbopumps is described and examples of flowfields are discussed to illustrate that physics based models and analytical calculation procedures based on computational fluid dynamics (CFD) are needed to develop reliable design procedures for turbopumps. A CFD code developed at NASA ARC was used as the base code. The turbulence model and boundary conditions in the base code were modified, respectively, to: (1) compute transitional flows and account for extra rates of strain, e.g., rotation; and (2) compute surface heat transfer coefficients and allow computation through multistage turbomachines. Benchmark quality data from two and three-dimensional cascades were used to verify the code. The predictive capabilities of the present CFD code were demonstrated by computing the flow through a radial impeller and a multistage axial flow turbine. Results of the program indicate that the present code operated in a two-dimensional mode is a cost effective alternative to full three-dimensional calculations, and that it permits realistic predictions of unsteady loadings and losses for multistage machines

Experiments on grain yield in a range of old and modern wheat varieties.

Growth, yield, water use and water use efficiency of old and modern wheat varieties in a mediterranean type environment, 87M17 and 87WH14. Ear and stem dry matter at anthesis and grain yield in a range of wheat varieties, 87M18

Long term effects of direct drilling and conventional cultivation on the distribution of nutrients and organic c in soils of south Western Australia

This experiment was part of a long term tillage trial designed to examine the effect of various tillage systems on the yield of wheat on a range of agricultural soils in Western Australia. A subset of results from the main experiment is presented here.This report describes the distribution of extractable P, extractable K, total N, organic C, and pH at 6 depths in the soil from 6 locations; Wongan Hills, Merredin (H) (calcic, red-brown earth), Avondale, Merredin (L) (acid, yellow earth), Esperance and Mt Barker. Three tillage systems (conventional cultivation, direct drilled with a combine, direct drilled with a triple discdrill) and 2 nitrogen rates were applied, to sites of continuously cropped wheat. Developments were monitored for a period of 9 years.The concentrations of extractable nutrients and organic C in the surface layers of the soil were generally higher with direct drilling than with conventional cultivation. Differences between treatments were generally evident within the first three years of the experiment. The effect of tillage tended to be similar at all locations except Esperance, where tillage had no effect on the concentration of extractable nutrients or organic C in the soil. Conventionally cultivated sandy and sandy clay loam soils also tended to have a slightly higher pH than direct drilled soils

Expert Leadership and Hidden Inequalities in Community Projets

This chapter explores the development of a mid-range theory that can be used in organisations when considering how to engage multiple stakeholders in a project that requires expert input. The case study presented here is concerned with a ground-breaking approach to integrate heritage, culture and social benefit through the medium of archaeology and heritage. The findings indicated that the ‘expert’ as a leader of the project created hidden inequalities in the team, preventing the longer-term social outcomes of the project from materialising. A Realist Evaluation (Pawson and Tilley, 1997a) protocol was developed which created an ‘intervention’, permitting the non-linear complex interactions between multiple groups and multiple stakeholders to be observed and evaluated. This allowed for the political, strategic, organisational, operational and individual perspectives to be addressed making it a suited evaluative approach to this type of multiple stakeholder project