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The crush behaviors of hollow square columns made of 45 different materials with emphasis on aluminum alloys and at two impact energy levels were simulated with FEA software DYNA3D. The force response curves based on the FEA simulation results were studied. Analysis of variance, cluster analysis, and principal component (PC) analysis were employed to analyze the data with SAS programs. The regression equations for calculating the peak force and time duration are given. The significance of the material properties and the impact energy levels to the peak force and the time duration are discussed. Finally, a procedure to predict the force response characteristics for a new material was suggested based on the current established database.

The rate of energy absorption during the plastic deformation of structural components is an important factor in the design of automotive safety systems such as chassis crumple zones. This paper describes a design tool for predicting energy absorption characteristics. The tool was based on measurements of the energy absorption rates of twenty-three selected materials subjected to three impact energy conditions. A well-established finite element code, LS-DYNA3D, was used with a mesh representing a hollow column of square cross-section to establish a database of energy absorption characteristics. A mathematical model representing the energy absorption rates was determined and the material properties most influencing the energy absorption rates were identified. A parabolic model best represented the energy absorption charactersitics. The regression coefficients for the model were determined for all tested materials under the selected test conditions.

The objective of this study is to relate energy absorption characteristics to selected material properties and to establish a methodology that allows one to determine some of the material properties for maximum energy absorption. The finite element program DYNA-3D and its associated pre and post processors were used. The model used is a hollow square column. Five properties of the materials were included in the analysis: (i) Density (ii) Elastic Modulus (iii) Tangent Modulus (iv) Yield Strength, and (v) Poisson Ratio. The Response Surface Method in conjunction with the canonical analysis were employed to locate the optimum or near optimum levels of the properties and then to determine the equation of the response surface in an area near the vector of optimum levels. For the given levels of three out of five material properties used in the study, one can calculate the remaining two material property levels to achieve the near-optimal energy absorption.

This study relates the structural stiffness and kinetic energy of impact (between 34 J and 136 J) to the resulting contact force and duration of force rise for a square tube with wall thickness between 12.7 mm and 25.4 mm. LS-DYNA3D, finite element program was used for the analysis. Two materials, AISI 4340 and AISI 301 steel, are used as examples. Regression equations for predicting the relationship between the structural stiffness, maximum force and duration of force rise are given for each material.

A new type of centrifugal pump which can be used for transportation of alternate fuels such as coal slurries was tested. Design and performance of the pump, and analysis of the fluid flow in the pump is presented. The unique internal flow pattern, which was determined using a high speed camera, results mainly from the recessed impeller design and the geometry of the blades. The qualitative and quantitative analysis of the flow profiles indicate the existence of suitable conditions for a decrease in the direct contact of the abrasive particles of the slurry with the interior surface of the pump which translates to longer maintenance-free performance. The test pump performance for slurries at higher concentrations compared well with the existing slurry pumps. The highest concentration used during the test was 60% by weight. At this level the maximum efficiency of the pump was 30%. The corresponding power required and the flow rate were 5.97 kW and 528 L/min, respectively.

The development of a fuel-air injection nozzle that injects a premixed fuel and air and then a quantity of clean air into the combustion chamber is described. The new injection nozzle provides better controllability of fuel-air mixing and fuel evaporation. Additionally, the clean air injection following the fuel-air mixture injection prevents stagnant fuel accumulations in the nozzle tip. Therefore, the fuel-air injection nozzle is of particular advantage for use with difficult fuels such as plant oils for long term operation. The fuel-air injection nozzle was tested in an engine running on sunflower oil giving significant reduction in carbon buildup. No engine modifications were necessary for the fuel-air injection nozzle installation.

The flow of diesel fuel through multi-hole injection nozzles is well understood. There are, however, no comprehensive experimental results for the design of injection nozzles for alternate fuels. A steady state flow generator was designed and employed to analyze the effects of the physical fuel properties and the needle lift on the discharge coefficient for the nozzle orifice. Three fuels were tested: diesel reference fuel, a 50/50 mixture of diesel fuel and sunflower oil, and 100%. sunflower oil. The fuel viscosities range from 3.0 cS to 30.0 cS at 40°C. Five injection pressures ranging from 3.5 to 13.8 MPa, and eight increments of needle lift between 0.031 and 0.940 mm were used in this investigation. A significant influence of needle lift, injection nozzle pressure, and physical properties of fuels on the flow coefficient in the normal operating range of a typical diesel engine was proven.

The effect of increased clearance between the needle and its guides in a fuel injection nozzle on the rate of lacquer deposit formation from neat sunflower oil was investigated. Bosch fuel injection nozzles were tested on a fuel v injection calibration stand. The needle clearance reduction due to deposit buildup was monitored with a pneumatic leak test. Two test series of 100 hours duration each were performed at a temperature of 350°C. Each series consisted of ten 10-hour segments with a complete system shutdown after each segment. For the first test series the system was allowed to cool down before each shutdown. During the second test series the system was stopped while still hot. For fuels with physical and chemical properties similar to those of neat sunflower oil, excessive residue on the internal surfaces of the injection nozzles is likely to occur with the ultimate result of complete needle immobility.

The effect of temperature on the rate of lacquer deposit formation from neat sunflower oil on the needles of fuel injection nozzles was investigated. Boson fuel injection nozzles were tested on a fuel injection calibration stand. A pneumatic leak test was developed to monitor the needle clearance reduction due to deposit buildup. For fuels with physical and chemical properties similar to those of neat sunflower oil, excessive residue on the internal surfaces of the injection nozzles is likely to occur with the ultimate result of complete needle immobility. The rate of the lacquer buildup on the needle increases with temperature. Prior to final needle sticking, delay in start of injection, sluggish needle lift, increases in duration of injection, maximum, final residual, and maximum residual line pressures, and decrease in maximum needle lift can be observed. Based on the obtained results, the temperature of injection nozzles handling plant oil fuels should be kept as low as possible.

A numerical optimization technique has been applied in order to obtain the optimum level of some design variables of the diesel fuel injection nozzle. A description of the optimization procedure is provided together with a discussion of the physical and mathematical flow model used. Sample applications of the optimization procedure addressing design of a fuel injection nozzle consideration along with comparisons among three different fuels are presented. The fuel injection mean rate, the diameter of the injection cavity, and the diameter of the injection orifice were used as the objective functions in different aspects of the optimization procedure. Chosen design variables were: the angle of the needle tip, the diameter of the nozzle injection cavity, and the injection orifice diameter. Some constraints characterizing the operating conditions of the injection nozzles were taken under consideration.

Multivariate statistical procedure has been used to compare various alternate fuels based on the residue formation on selected engine parts. The results from the Multivariate Analysis of Variance procedure which does the simultaneous comparison of the chosen response variables are presented. The assumptions for this test procedure are given. Problems which could affect the validity of the statistical procedures for the endurance test are discussed. Data from a 200-hour EHA laboratory screening endurance test is used to illustrate the statistical methods. Results from the statistical analysis of the experimental data were in close agreement with the engineering interpretation of the observed differences between fuels. Critical engineering interpretation of the statistical results is still required due to the high sensitivity of the statistical analysis.

Five T31 turbochargers used on a direct-injected diesel engine were tested as part of a plant fuel evaluation program. The engine was tested on the 200-hour durability cycle proposed by the Engine Manufacturer's Association (EMA). Part of the evaluation was an investigation of premature carbon and lacquer deposits, and wear within the turbocharger due to oil deterioration from the hybrid fuels. The lubricant viscosities for all tested fuels, except the microemulsion, were within normal limits. A sudden increase in lubricating oil viscosity for the microemulsion was observed. At the same time, higher blow-by and increased lubricating oil consumption was noted. All turbochargers displayed journal bearing wear but no rubs or unusual seal leakage was formed. The turbine shafts showed various degrees of hot shutdown and high temperature operation for different fuels. The turbine wheels and housings varied in color from a soft gray to dark black.

A new statistical procedure to use with the Engine Manufacturers Association 200 hour duraability test for alternate fuels evaluation has been proposed. Data from a laboratory endurance test is used to illustrate the proposed statistical procedures. The assumptions for each statistical test are given. Further, problems encountered during the endurance test which affected the validity of the statistical tests are discussed.

An unmodified, direct-injected diesel engine was operated on diesel fuel and three blends of diesel fuel and sunflower oil. Heating of the fuels was used to change their viscosities. At normal fuel temperatures, specific fuel consumption and smoke emission increased for any power as sunflower oil content increased. Overall efficiency and exhaust temperature showed virtually no changes with fuel composition. Increasing fuel temperature caused a shift of best overall efficiency from high to low speeds, the magnitude of the shift depending on the plant oil concentration of the fuel. Thus fuel heating as a means of viscosity control may result in an efficiency penalty in the normal operating range of an engine. Typical plant oil induced engine contaminations such as wet stacking, excessive carbon accumulations, nozzle orifice blocking, and lubrication oil gelling were experienced.