Comparative Evaluation of Sawdust with Different Casing Materials for the Production of Agaricus bisporus (Lange) Imbach under Natural Bamboo Hut Conditions

Studies were conducted to evaluate leached sawdust as a casing substrate for the cultivation of Agaricus bisporus either alone or in combination with other substrates at College of Horticulture and Forestry, Neri, Hamirpur, Himachal Pradesh, India during the year 2018–2020. Out of seven casing media evaluated alone, coconut coir pith performed best in terms of all production parameters like time for spawn run (20.3 days) and pinning (15.7 days), sporocarps’ number (55.33), yield (0.679 kg 5 kg-1 compost) and biological efficiency (33.95%). The efficiency of sawdust- leached improved with the addition of other casing substrates. In commercial trial, combination of sawdust - leached with coconut coir pith, spent compost and farmyard manure (1:1v/v) performed better as compared to control (FYM+local soil), but a combination of sawdust- leached+coconut coir pith (1:1v/v) proved to be the best in terms of sporocarps’ number (88.00) and yield (1.271 kg 10 kg-1 compost) despite of the delay in time for spawn run (26 days) and pinning (24.3 days). Casing media also affected the biological efficiency of compost which varied from 10.50% in local soil to 34.05% in sawdust- leached+farmyard manure (1:1v/v) in different experiments. Cap diameter was recorded to be maximum (41.37 mm) in 2 years old spent compost and minimum (34. 27 mm) in sawdust- leached while, stipe length ranged from 14.17 mm in vermicompost-leached to 22.90 mm in sawdust- leached+farmyard manure (1:1v/v). However, fruit bodies harvested from all the casing treatments including standard check were found to be silky smooth and firm to compact.

Optimization of Slots-Groove Coupled Casing Treatment for an Axial Transonic Compressor

A multi-objective optimization of a coupled casing treatment (CCT) for an axial transonic compressor is performed in this study. The coupled casing treatment is the basis axial slots with a circumferential groove located at various positions along the slots. During the optimization stage, five important parameters to control the geometry are used as the optimal variables. The stall margin and the peak efficiency are selected as the optimal objectives. Non-dominated sorting genetic algorithm II coupled with radial basis function (RBF) approximation is used to search for Pareto-optimal solutions. Then, four optimal configurations are selected from Pareto-front for further analysis. As shown in the simulation results with and without the coupled casing treatments, the leakage flow is reenergized and the blocking region near the blade leading edge at rotor tip is decreased by the use of these structures under the low flowrate condition, which is the main reason for stability enhancement. Besides, a coupled casing treatment with the groove settled near the end of the basis slots have the potential to generate more injection flow and extend the operating range of compressor further.

Structural Analysis of an Auxetic Casing Structure Incorporating Tip Blowing Casing Treatment Modification

In axial compressor design for aero engines high system efficiency and operational stability are two main objectives. Both depend on clearance-induced losses. Previous investigations at the Institute have resulted in a passive clearance controlled compressor design using additively manufactured auxetic casing structures. The extension to an active clearance controlled device to keep an approximately constant tip gap ratio during the entire flight mission is currently investigated. Constructive on these deliverables, the implementation of tip blowing casing treatment modification in a double-walled compressor casing including an auxetic inner structure is covered in this work and studied for maximum load conditions by means of Finite Element Analysis. The idea to supplement the current auxetic casing construction with casing treatment modification emerges from the aspiration to generate further stability improvements in the high-pressure domain and the exploitation of the design freedom provided by additive manufacturing. Key issues addressed in this work by conducting parameter studies are casing treatment positioning and corresponding structural correlations depending on circumferential quantity. The evaluation section concentrates mainly on the calculated stress level associated with tip blowing casing treatments because this value is crucial for prospective fatigue predictions. In order to compare the results, the auxetic casing structure without casing treatment modification serves as reference. Promising solutions for local stress reductions are also proposed and discussed. From a structural mechanics perspective, the casing treatment modification generates very high and comparable notch stress levels at each position. Placing the casing treatments at the framework of the auxetic cells and splitting the inner casing ring results in tolerable stress levels.