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An aerodynamic shape optimization algorithm is presented, which includes all aspects of the design process: parameterization, flow computation and optimization. The purpose of this paper is to show that the Class‐Shape‐Refinement‐Transformation method in combination with an Euler/adjoint solver provides an efficient and intuitive way of optimizing aircraft shapes.

The Class‐Shape‐Transformation method was used to parameterize the aircraft shape and the flow was computed using an in‐house Euler code. An adjoint solver implemented into the Euler code was used to compute the required gradients and a trust‐region reflective algorithm was employed to perform the actual optimization.

The results of two aerodynamic shape optimization test cases are presented. Both cases used a blended‐wing‐body reference geometry as their initial input. It was shown that using a two‐step approach, a considerable improvement of the lift‐to‐drag ratio in the order of 20‐30 per cent could be achieved. The work presented in this paper proves that the CSRT method is a very intuitive and effective way of parameterizating aircraft shapes. It was also shown that using an adjoint algorithm provides the computational efficiency necessary to perform true three‐dimensional shape optimization.

The novelty of the algorithm lies in the use of the Class‐Shape‐Refinement‐Transformation method for parameterization and its coupling to the Euler and adjoint codes.

The purpose of this study is to examine what the most significant aspects of environmental sustainability in the forest biorefinery sector are and what kind of criteria should be applied to an evaluation of environmental sustainability in the forest biorefinery context.

The topic is approached by themed interviews in Scandinavia and North America with 23 representatives from the forest and bioproducts sectors. The interviews were examined using the thematic analysis method.

The study indicates that environmental sustainability may be an important driver for the forest biorefinery business. From the perspective of environmental sustainability, harvesting feedstock will be the most challenging part of the value chain to manage. Raw material availability and its sustainability, life‐cycle perspective and beneficial products were the most important criteria in the environmental sustainability assessment of forest biorefinery value chain companies.

A sector‐specific guideline was formulated for the most important criteria to be included in an environmental sustainability assessment of forest biorefinery value chain companies. The criteria comprise the first step of a more elaborate evaluation framework, which can provide more accurate information about the sustainability performance of biorefinery value chain companies. The criteria can encourage companies to analyze environmental sustainability challenges holistically, increase a company's transparency for its stakeholders and offer information to investors about the environmental status of the company.

The novelty of the study lies in the sector‐specific, holistic environmental sustainability evaluation in the emerging forest biorefineries.