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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.

This study relates the structural stiffness and kinetic energy of impact to the dynamic response of a belted vehicle occupant. Acceleration time histories of impact for structures with different stiffnesses were obtained by performing a finite element analysis using the LS-DYNA3D finite element program and a model representing a structural member made of AISI 4340 steel. For the human body dynamics analysis, the Articulated Total Body (ATB) computer program was used to perform six simulations of a 50 percentile male restrained by a 3-point seatbelt system for a co-linear -Gx impact.

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.

This paper presents the evaluation results from the EMA durability test on 25% high oleic sunflower oil/75% diesel fuel and 25% high oleic safflower oil/75% diesel fuel. The test results from both fuels were compared to the outcome for a standard diesel fuel. The fuels were compared based on the performance and emissions results including; power output, fuel consumption, CO, CO2, NO and HC and the carbon and lacquer residue formation on the internal parts of the engine. The results indicated no significant change in engine performance for the tested fuels, throughout the duration of the investigation. The carbon and lacquer residue formations were within a normal range for both fuels in comparison to the results from the fuel for standard diesel fuel.

This paper presents the evaluation results from the analysis of different blends of fuels using the 13-mode standard SAE testing method. Six high oleic safflower oil blends, six ester blends, six high oleic sunflower oil blends, and six sunflower oil blends were used in this portion of the investigation. Additionally, the results from the repeated 13-mode tests for all the 25/75% mixtures with a complete diesel fuel test before and after each alternative fuel are presented.

The paper* describes the analysis of experimental results of a laboratory flow apparatus used to measure the energy released during premixed combustion at atmospheric pressure in near quiescent air. The flow apparatus, described in a parallel paper, has the means to provide air temperatures in the range between 800 and 950° K. An infrared radiation detector and a photodiode sensitive to radiation in the visible range of the electromagnetic spectrum monitor the events taking place inside the combustion chamber through a sapphire lens. A beam splitter permits simultaneous observation of the combustion events by both sensors. The difference in response times between the two sensors offers information about the non-luminous premixed combustion. Four fuels, No. 2-D diesel fuel, a 50/50% volumetric mixture of diesel fuel and sunflower oil, neat sunflower oil, and neat high oleic safflower oil were used.

The paper* describes the design and operation of a laboratory combustion chamber used to study the energy released during the premixed burning phase of diesel combustion. The flow apparatus operates at atmospheric pressure and has the means to provide near quiescent air at temperatures in the range between 800 and 950° K which is the typical temperature range at the end of compression stroke in a diesel engine. A rotary injection pump with a trigger mechanism delivers equal amounts of fuel to an injector, which sprays it into the constantly replenished supply of fresh, hot air for combustion. An infrared radiation detector and a photodiode sensitive to radiation in the visible range of the electromagnetic spectrum monitor the events taking place inside the combustion chamber through a sapphire lens. A beam splitter permits simultaneous observation of the combustion events by both sensors.

Field tests for a variety of fuels on different tractor engines were carried out during the summers of 1981 through 1986. Fuels tested included alkali refined and winterized sunflower oil blended with diesel fuel, crude degummed sunflower oil blended with diesel fuel, high oleic safflower oil blended with diesel fuel, methylester of sunflower oil, or soybean oil. Blends of either 25% vegetable oil and 75% diesel fuel or 50% vegetable oil and 50% diesel fuel were used. Methylesters were not blended with diesel fuel. The manufacturers that participated in the project were John Deere, J.I. Case and Allis Chalmers. The project indicated that farm diesel tractors can be operated on any of the fuels that were tested. Care should be taken, however, since some signs of premature engine problems were observed. In general, continued use of these fuels cannot be recommended at this time.

The paper describes engine modifications, which are proposed to provide a means to overcome the adverse effect of sunflower oil fuel on diesel engines' longevity. The proposed system consists of a dual fuel system and fuel preheater. The dual fuel system was designed to eliminate engine conditions that are responsible for the majority of the problems associated with the use of sunflower oil fuel. Specifically, the dual fuel system will (1) prevent the operation of an engine on alternative fuels at low-load, low-speed conditions, (2) reduce the exposure time of the fuel injection system to the sunflower oil at the excessively high temperature conditions during the transition process from high to light loads, (3) eliminate the conditions (such as cold start-up) at which the fuel temperature is too low for acceptable atomization, and (4) eliminate the exposure of the fuel injection system to sunflower oil during the shut-down period.

A neat, alkali-refined sunflower oil, a 50/50 blend (v/v) of sunflower oil and #2 diesel fuel, and 100% #2 diesel fuel were evaluated in a direct injected, one-cylinder Petter engine according to the SAE 13 mode test procedure. The experiment was conducted to evaluate the effects of plant oil based alternative fuels on exhaust emissions and to simultaneously compare the test fuels. Additionally, the effect of engine load and speed on the exhaust emissions using the plant oil alternative fuels was statistically evaluated. The response variables were CO, NO, HC, and smoke. The predictor variables were the concentration of sunflower oil in the test fuel, the engine speed, and load. A multivariate test and covariance analysis were used for the results evaluation.

The paper describes experimental validation of a laboratory flow apparatus used to measure the ignition delay times of diesel fuels at atmospheric pressure in near quiescent air. To validate the proposed method the experimental data were compared with the results from the studies performend on non-engine combustion chambers with continuous air flow at atmospheric pressure and various temperatures. The proposed flow apparatus, described in an earlier paper, has the means to provide air temperatures in the range between 650 and 730°C. An infrared radiation detector monitors the evolution of the temperature inside the combustion chamber. Ignition delay is measured as the time interval between the beginning of the needle lift and the beginning of increase in infrared radiation detected by the sensor. Six test fuels were used.

The paper describes the design and operation of a laboratory combustion chamber used to measure the ignition delay times of diesel engine fuels at atmospheric pressure in near quiescent air. The flow apparatus has the means to provide air temperatures in the range between 650 and 730°K which is the typical temperature range at the end of the compression stroke in a diesel engine. An injection pump with a trigger mechanism delivers equal amounts of fuel to an injector, which sprays it into the constantly replensihed supply of fresh, hot air for combustion. An infrared radiation detector monitors the evolution of the temperature inside the combustion chamber. Ignition delay is measured as the time interval between the beginning of the needle lift and the beginning of increase in infrared radiation detected by the sensor. Test results for two fuels are presented and compared with the results from previous studies performed under similar test conditions.

The application of a multiple polynomial regression procedure for optimization of design and performance parameters has been presented. To illustrate the statistical method, data from a laboratory test of an exhaust emission reduction device was used. There were four factor variables for which the response was constructed. Among the factor variables two were design parameters; the remaining two were the operating parameters. The selected response variables were CO, NO, and HC's. The assumptions for the analysis procedure are presented. Problems which could affect the validity of the statistical procedures for the design optimization are discussed. Experimental verification of the optimization results was performed. Overall agreement between the predicted level of pollutants reduction and measured values did not differ by more than ten percent.

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 multivariate statistical procedure has been used to compare various alternate fuels based on the long term engine performance. The results from the multivariate analysis of covariance procedure, which does the simultaneous comparison of the chosen response variables, were adjusted for time of engine operation since the time factor was found to be significant. The assumptions for this test procedure are presented. Problems which could affect the validity of the statistical procedures for the laboratory endurance test are discussed. To illustrate the statistical method, data from a laboratory screening endurance test was used. Results of the analysis were in close agreement with the engineering interpretation of the observed differences between fuels.