The present study analyzed the effect of temperature, pH, pre-treatment and mixing ratio on the anaerobic digestion process. The parameters during the anaerobic co-digestion of cow manure and food waste were then optimized using the Taguchi experimental design method. ANOVA was carried out to find the significant parameters which influence biogas production. Experimental tests were carried out at laboratory-scale reactors kept at different temperatures (28 °C, 35 °C, and 50 °C). The specific methanogenic performance (SMP) during anaerobic digestion at higher temperatures was characterized with the analysis of acetate, propionate, butyrate, hydrogen, glucose, and formate, and was validated with the literature. The improvement of biogas production with different pre-treatments, i.e., ultrasonic, autoclave, and microwave techniques, was also analyzed. The results showed that the reactor that was maintained at 35 °C showed the highest biogas production, while the reactor that was maintained at a lower temperature (28 °C) produced the lower volume of biogas. As the retention time increases, the amount of biogas production increases. Methanogenic activities of microorganisms were reduced at higher temperature conditions (65 °C). Biogas production increased by 28.1%, 20.23%, and 13.27% when the substrates were treated with ultrasonic, autoclave, and microwave, respectively, compared to the untreated substrate. The optimized condition for the highest biogas production during anaerobic co-digestion of food waste and cow manure is a temperature of 35 °C, a pH of 7 and a mixing ratio (CM:FW = 1.5:0.5). ANOVA showed that temperature is the most important input parameter affecting biogas production, followed by mixing ratio.

The present study aims to optimise the material parameters of the 2xxx series aluminium alloy used in aircraft wing leading edges to improve its mechanical properties against bird impact. For this study, a bird model is established and validated with an experiment test from literature and with a bird strike test on the wing leading edge. The significant material parameters which affect the energy absorption characteristics of the wing leading edge is selected from the comparison of parametric study results. Then the selected parameters are optimised and validated with bird impact analysis studies based on Taguchi’s L16 factorial design of experiments combined with grey relational analysis. The significant improvement in the mechanical properties, i.e. yield strength, ultimate tensile strength, and tensile toughness of the new optimised aluminium alloy has been proved with a series of uniaxial tension tests. The new alloy shows average property improvement up to 24.44% in tensile toughness and 19.4% in tensile strength than baseline alloy AA 2024-T3.

The $2\mathrm{x}\mathrm{x}\mathrm{x}$ series aluminum alloys are preferred as a material for aircraft leading edges because they have high failure strain compared with other aluminum alloys. This parametric study on $2\mathrm{x}\mathrm{x}\mathrm{x}$ series aluminum alloy material parameters was carried out to identify the critical parameters that influence the energy absorption and load transferability during bird strikes. The soft-body impact simulation on an aluminum alloy leading edge was validated with an experiment test. Using commercially available finite-element software, a parametric study has explored the bird impact response of aluminum leading edges with different material parameters. The results showed that static yield limit, elastic modulus, strain-hardening modulus, and strain-hardening exponent are the most influencing material parameters to be considered to improve the crashworthiness performance of the aluminum alloy. Analysis of variance revealed that the most significant material parameters for the performance improvement of the wing leading edge against bird impact are the elastic modulus and static yield limit. After that, considering this material parameters as design variables, a gray relational analysis was carried out to simultaneously reduce reaction force at the spar region and wing center tip deformation. The material parameter values were selected from the optimization study, and a comparison analysis was carried out to study the improvement of the optimized material properties. The optimized aluminum alloy showed up to 25% improvement in energy-absorbing characteristics than a conventional aluminum alloy (AA 2024-T3). Fracture analysis was carried out to find the optimized aluminum alloy’s damage initiation and evolution parameters.

The response of aluminium plate with optimized material parameters against soft body impact is explored with finite element software ABAQUS/Explicit. Initially, a soft body model was created and verified with an experiment test. The material attributes of the Aluminium Alloy (AA) wing leading edge have been optimized with reducing maximum reaction force and wing centre deformation concurrently. The soft body impact simulations have been done on aluminium alloy plates to compare the property improvement of the developed aluminium alloy to that of conventional aluminium alloy used for wing leading edges. The results showed that the plates with developed aluminium alloy exhibit lesser reaction force and centre deformation than that of AA 2024-T3. The reduction of wing centre deformation and reaction force help to protect the wing components and supporting structures respectively. From the results, it could infer that the developed aluminium alloy can resist bird impact effectively by absorbing most of the impact energy without transferring it to supporting structures.