An Evaluation Method for Automotive Technical and Comprehensive Performance

An objective evaluation scheme for automotive technical and comprehensive performance could provide critical and instructive insights for academic research,engineering practice,and commercial marketing of vehicles.In this paper,the technical performance index A=S∕T_(1)⋅T_(2)(m∕(s^(2)⋅L))and comprehensive performance index F=M⋅S∕T_(1)⋅T_(2),(kN⋅L^(−1),where M is the vehicle mass)are formulated by incorporating the vehicle 0–100 km⋅h^(−1) acceleration duration T_(1),100–0 km⋅h^(−1) braking duration T_(2),and fuel economy S(mileage per liter fuel at constant speed)to assess the vehicle’s longitudinal dynamic performance.A and F offer a clear physical implication of a vehicle’s acceleration capability and traction efficiency acquired per unit of fuel consumption,respectively.These indexes are used for wide case studies of popular market sedans and SUVs of joint ventures(JVs)and domestic brands in China over the last 17 years.The findings prove that this approach could be effectively and reliably utilized for the objective evaluation and analysis of the technical and comprehensive performance of automotive models.

Influence of Mango Feed-Based Diets on the Production and Economic Profitability of Montbeliarde Cows’ Milk at the End of Lactation in Burkina Faso

The study evaluated the effects of a diet incorporating a mango-based feed on the technical-economic performance of milk production of Montbeliard cows at the end of lactation in a dairy farm in Bobo-Dioulasso, Burkina Faso. To do so, 14 cows were subjected to 3 diets, including an experimental diet incorporating mango (ED) in comparison to a balanced control diet (BCD) and to the feeding practice of the farmer (FCD) during 60 days. Results show that the average amount of milk milked per day from ED (10.93 ± 0.17 L) was significantly higher (p < 0.05) than BCD (8.80 ± 0.19 L) and RTA (5.39 ± 0.14 L). The conversion index of FPD (4.24 ± 0.14) was significantly higher (p < 0.05) than that of BCD (1.75 ± 0.19) and ED (1.26 ± 0.16). Average feed costs per liter of milk (FC/L) were significantly different (p (125.95 ± 4.56 FCFA), BCD (83.67 ± 6.36 FCFA) and ED (60.06 ± 5.49 FCFA). The average gross profit margins (GPM) were significantly higher and decreasing (p ,953 ± 5031 FCFA), BCD (167,157 ± 5831 FCFA) and FCD (74,188 ± 4185 FCFA). Mango feed can be used in the diet of dairy cows. Its use contributes to the reduction of production costs and the generation of substantial profits. The valorization of mango residues is an alternative for a greater availability of feed at lower cost for the animals. It could contribute to a better management of processing residues that pollute the environment and to the reduction of fruit flies that affect orchard yields through reinfestation. The increased use of mango in dairy cattle feed should be encouraged.

Performance assessment of simple and modified cycle turboshaft gas turbines

This paper focuses on investigations encompassing comparative assessment of gasturbine cycle options.More specifically,investigation was caried out of technical performanceof turboshaft engine cycles based on existing simple cycle(SC)and its projected modifiedcycles for civil helicopter application.Technically,thermal efficiency,specific fuel consump-tion,and power output are of paramount importance to the overall performance of gas urbineengines.In course of carrying out this research,turbomatch software established at CranfieldUniversity based on gas turbine theory was applied to conduct simulation of a simple cycle(baseline)two-spool helicopter turboshaft engine model with free power turbine.Similarly,some modified gas urbine cycle configurations incoporating unconventional components,such as engine cycle with low pressure compressor(LPC)zero-staged,recuperated enginecycle,and intercooled/recuperated(ICR)engine cycle,were also simulated.In doing so,designpoint(DP)and off-design point(OD)performances of the engine models were established.Thepercentage changes in performance parameters of the modified cycle engines over the simplecycle were evaluated and it was found that to a large extent,the modified engine cycles withunconventional components exhibit better performances in terms of thermal efficiency andspecific fuel consumption than the traditional simple cycle engine.This research made use ofpublic domain open source references.