A novel optimisation process has been proposed in this paper to maximize the aerodynamic efficiency of a modern fan blade while satisfying the structural constraint imposed by the material limits. The method developed is based on the discrete adjoint for the aerodynamic efficiency sensitivity evaluation with the structural constraint provided by a response surface method for the structural stress. To facilitate a large number of sampling points required in the response surface generation, a fast, meshless method was used for the stress calculations. The method was applied to the optimisation of a practical fan blade, representative of modern, high-bypass-ratio turbofan jet engines. It is demonstrated that the fan blade efficiency can be improved by 0.6% while maintaining the stress below a prescribed value of 500 MPa assuming a titanium alloy material. It is shown that without the stress constraint, the efficiency benefit is larger, namely 0.9% but the maximum stress value increases considerably beyond the material’s acceptable criterion, to almost 1000 MPa. The method is built in a modular way and can be adapted to accommodate a range of different turbomachinery blade designs. Flutter analysis for the optimised fan blade has also been carried out due to its practical importance.

The paper presents high frequency pointwise measurements of pressure and temperature carried out on a shock wave generator consisting of a couple of supersonic jets impinging on a Hartman oscillator system. The shock wave generator was developed as a means to achieve an aerodynamically controlled pulsed detonation chamber. The analysis allows the selection of the optimal geometry and inlet conditions for such an application. The effect of the inlet conditions and of the geometry of the experimental model on the frequency and amplitude of the pressure waves occurring in the system is analyzed. The paper also presents the effects of other geometrical parameters: the critical section of the jet nozzles, the volume ratio of the resonator geometry, and the inlet angles of the jets. Effects of inlet pressure and temperature are also included.

The paper presents a numerical algorithm for the theoretical calculation of the thermodynamic cycle of a pulsed detonation based engine, based on the Zeldovich – von Neumann – Doring detonation model, together with the algorithm employed to perform them, and a numerical application. The results are compared to numerical data obtained for the Chapman – Jouguet detonation thermodynamic parameters using the NASA – Glenn Chemical Equilibrium Program CEA2. As a reference, the thermodynamic cycle of a Brayton engine operating under the same conditions of compressor pressure ratio and fuel mass flow rate is computed and included in the paper. It is found that the CEA2 detonation model predicts a very low engine thermodynamic efficiency, while the ZND model yields a higher efficiency of the detonation based engine with respect to the Brayton cycle engine. The specific work of the detonation engine is higher than the Brayton engine, but the power remains lower.

The paper presents the total pressure experimental measurements carried out at the Romanian Research and Development Institute for Gas Turbines COMOTI in order to determine the total pressure losses in the Inter - Turbine Duct of a two spools gas turbine, as a function of the gas turbine operating regime (mass flow rate) and rotational speed. The Inter - Turbine Duct experimental assembly has been designed, manufactured and tested at COMOTI. The total pressures were measured as a function of the pre-swirling angle, which simulates the influence of the high pressure turbine rotational speed located upstream of the Inter turbine duct in the real gas turbine, as well as for three operational regimes, without the pre-swirlers modules. The results indicate that the total pressure loss along the Inter - Turbine Duct is of maximum 0.9 %. The lowest overall total pressure loss occurs at 0o pre-swirling angle, around 0.8%, while along the ITD struts, the lowest pressure loss is obtained for a 15o pre-swirling, below 0.1%. The influence of the operating regime on the total pressure loss was found to be linearly, the pressure loss increasing with the reduced mass flow rate, between 1% and 1.9% overall, and between about 0.1% and 0.4 % along the struts.

This work presents a first-iteration bio-faithful dragonfly-inspired wing designed for future flapping micro air vehicle (MAV) applications. Using high-resolution imaging, the natural venation pattern of fore- and hindwings was reconstructed in CAD and reproduced through high-precision stereolithography at 1:1 and 3:1 scale. The printed polymeric wings successfully preserved the anisotropic stiffness distribution of the biological structure, enabling realistic bending and torsional responses. Modal analysis and dynamic testing confirmed that the lightweight designs operate within the biologically relevant 20–40 Hz range and that geometry and material choices allow predictable tuning of natural frequencies. Preliminary aerodynamic estimates captured the characteristic anti-phase lift behavior of four-wing flapping, while schlieren and infrared thermography demonstrated that heat dispersion and flow features follow the vein-driven structural pathways of the printed wings. Together, these results validate the feasibility and functional relevance of bio-faithful venation architectures and establish a solid foundation for future iterations incorporating membranes, full kinematic actuation, and higher-fidelity aeroelastic modeling.