Adam Dziubiński

Simplified thermo-fluid model of an engine cowling in a small airplane

Purpose – The purpose of this study is to developed a simplified thermo-fluid model of an engine cowling in a small airplane. An aircraft engine system is composed of different elements operating at various temperatures and in conjunction with the composite nacelle creates a region with high intensity of heat transfer to be covered by the cooling/ventilation systems. Therefore a thermal analysis, accounting for the complex heat transfer modes, is necessary in order to verify that an adequate cooling is ensured and that temperatures of the nacelle are maintained within the operating limits throughout the whole aircrafts flight. Design/methodology/approach – Simplified numerical simulations of conductive, convective and radiative heat transfer in the engine bay of the small airplane I-23 in a tractor arrangement were performed for different air inlet and outlet configurations and for varying conditions existing in air inlets during the flight. The model is based on the control volume approach for heat and ...

CFD ANALYSIS OF AGRICULTURAL AIRCRAFT AERODYNAMIC CHARACTERISTICS

this work is a preliminary part of project concerning the water droplets simulation in agricultural aircraft wake. the CFd results of flow calculation resulting in the aerodynamic characteristics of typical agricultural aircraft, on the example of PzL-106 „Kruk”, are presented in an operational range of the angle of attack and the sideslip angle. to obtain those characteristics a commercial rANS code was used. the two commonly utilized turbulence models: k-w SSt and Spalart-Allmaras are compared in terms of quantitative and qualitative results, especially in range of parameters when a flow separation occurs. the conclusions about range of use for both models are withdrawn. In order to obtain the flight configuration and conditions for final crop dusting simulation, the complete steady aerodynamic properties of the aircraft have been calculated, described and are available for other studies. Where available, the characteristics are compared with the experimental results. the results are also provided in form of distribution on the predefined aircraft parts, which is hard to obtain with the use of wind tunnel tests. keywords: CFd, agricultural aircraft, turbulence model.

CFD analysis of rotor wake influence on rooftop helipad operations safety

In the following work a real design of helipad and two example helicopters data are used to illustrate the methodology of using CFd in prediction of helipad operation safety. The analysis is limited to cases of hover, where the influence of the main rotor wake is dominant. both safety of helicopter and the on-deck helipad crew are taken into account, so the flow velocity on the helipad surface and pressure distribution are obtained as well as the wake – induced flow character near the well-shaped part of a building. The flow is solved using commercial code solving RANS equations with finite volume method. Spalart Allmaras turbulence model is used, since mainly the turbulent flow occurs on rotor wake, and flow is defined around blunt bodies. This method is proven to be useful for rotational fluid cases, and trimmed rotor modeling for hover near building cases. The results were used in design of the above mentioned helipad. keywords: CFd, helicopter safety, helipad, rotor wake.

Wind tunnel tests of the inverted joined wing and a comparison with CFD results

Purpose The purpose of this paper is to present the methodology and approach adapted to conduct a wind tunnel experiment on the inverted joined-wing airplane flying model together with the results obtained. Design/methodology/approach General assumptions underlying the dual-use model design are presented in this paper. The model was supposed to be used for both wind tunnel tests and flight tests that significantly drive its size and internal structure. Wind tunnel tests results compared with the outcome of computational fluid dynamics (CFD) were used to assess airplane flying qualities before the maiden flight was performed. Findings Extensive data about the aerodynamic characteristics of the airplane were collected. Clean configurations in symmetric and asymmetric cases and also configurations with various control surface deflections were tested. Practical implications The data obtained experimentally made it possible to predict the performance and stability properties of the unconventional airplane and to draw conclusions on improvements in further designs of this configuration. Originality/value The airplane described in this paper differs from frequently analyzed joined-wing configurations, as it boasts a front lifting surface attached at the top of the fuselage, whereas the aft one is attached at the bottom. The testing technique involving the application of a dual-use model is also innovative.

Aerodynamic analysis of General Aviation airplanes using computational fluid dynamics methods

Aerodynamic studies using fluid mechanics calculations were performed during the development of OSA and Flaris LAR-1 aircrafts. OSA is an aircraft of the Very Light Aeroplanes category (up to 750 kg of ground mass) for use. The Flaris LAR-1 is a lightweight jet made from modern carbon pre-impregnates for the fast and convenient transportation of four adults for business or recreational purposes. Dynamic development of microprocessor technology and computational fluid dynamics (CFD) enabled simulations of many phenomena occurring during the flow of body fluids. CFD is a division of fluid mechanics for detailed analysis and modeling of flows using numerical methods. In the theory of fluid mechanics, the movement of liquids and gases is described by the system of differential equations [1], which are: ● Navier-Stokes equation (momentum equation) in the form: