The effect of the inlet Mach number ratio and static temperature between supersonic subsonic flows on distortion characteristics recirculation zone downstream flameholder was experimentally investigated. fluid structure visualized measured by a calibrated particle image velocimetry system under subsonic–supersonic mixing flow, which constructed flat plate to divide rectangular flow channel. present results reveal that remains stable over wide range exhibits insensitivity changes in ratio....

Amidst the global energy crisis and progress in clean energy, this study aims to reduce design costs improve adaptability of turbines small ORC systems. It seeks offer enhanced renewable utilization methods for sustainable development. This paper focuses on performance an impulse single-stage turbine with partial admission analyzes it through numerical simulations using computational fluid dynamics (CFD). The investigates critical parameters under off-design conditions by varying inlet total...

The flow field characteristics downstream of the evaporative flameholder in subsonic–supersonic mixing were experimentally investigated. study focused on examining effects different inlet static pressure ratios characterized by supersonic and subsonic parameters. results indicated that increase ratio enhanced fragmentation multiple vortices located mainstream. It also exacerbated asymmetry recirculation zone strengthened tendency fluid to from one vortex another. regions with higher...

In view of the urgent demand for wide speed range and high-performance power next generation aircraft, near space multi-functional platform first stage TSTO (two-stage-to-orbit) transportation system, this paper timely puts forward an innovative turbo-rocket combined cycle propulsion scheme named NUAA-PTRE (Pre-cooled Turbo-Rocket Engine designed by Nanjing University Aeronautics Astronautics) under Ma 0–5. scheme, hydrocarbon fuel at normal temperature is employed to pre-cool incoming air,...

The setting machine exhaust gas contains a large number of fiber particles and micro oil droplets, which are adhesive flammable. This leads to difficulties in waste heat recovery the gas. In this article, numerical experimental studies non-uniform plate exchanger with dimples/protrusions for machines carried out. Based on three-dimensional fluid-thermal-structural coupling method, regenerative process between air investigated numerically low Reynolds turbulence model. effect structural...

This paper presents a summary of and introduction to research on high-altitude subatmospheric combustion concerning turbine scramjet engines. The investigation includes theoretical analysis, experimental studies, numerical simulations. analysis encompasses the flow field structure, fuel atomization, performance. Subsequently, recent performance liquid fuels, solid gaseous fuels under low-pressure plateau environments is reviewed. an evaluation flame height, temperature, rate, fire spread...

Low hemolysis is an important factor for axial blood pumps that has been used in patients with heart failure. The structure of impellers plays a key role the hemolytic properties pumps. Axial various exhibit different characteristic. In present study, we aimed to investigate type structures contain best low properties. Also, it expensive and time-consuming validate pump's property by vivo experiments. Therefore, numerical method was applied analyze pump. Specifically, pump calculated using...

A high-precision variable-thrust control method based on real-time measurement of pintle displacement and closed-loop feedback is proposed to solve the technical problems deep throttling regulation liquid rocket engines (LRE). By optimizing system structure parameters, with high precision a fast response under wide range variable thrust can be realized, thus large-range, fast-response, chamber pressure, equivalent thrust, indirectly realized. The pressure time not more than 0.3 s, overshoot...

A model for coupled dynamics of an airframe—propulsion integrated hypersonic air-breathing flight vehicle with various engine safety boundaries, called HIT-HAV (Harbin Institute Technology), was developed to analyse the couplings among dynamics, aerodyna-mics, propulsion, and control. These boundaries included inlet unstart boundary, burner wall temperature limitation, lean fuel combustion rich so on. All these were considered in modelling HIT-HAV. The validity practicability verified by...

A model of a NUAA-PTRE pre-cooled air turbine engine was established. The design point parameters the were optimized, including pressure ratio, flow rate compressor, efficiency, throat area, and efficiency turbine. at operating 142.73 kg/s. High performance key components under wide range working conditions realized after optimization. To achieve indicators overall scheme, adaptability studies conducted. three-stage variable geometry applied to inlet. pre-cooler optimized with...

The effect of surface roughness on the frictional characteristics liquid flow in microchannels with distributed rectangular elements is experimentally studied. velocity fields are obtained by micro particle image velocimetry (micro-PIV). friction coefficients 3%—7% relative higher than prediction based conventional theory due to additional pressure drag caused elements. existence gives rise disturbance laminar stream, and early transition turbulent rough validated.

A model of coupled dynamics for hypersonic air-breathing vehicle/engine had been developed to analyze the couplings among flight dynamics, aerodynamics, propulsion and integrated control. The validity practicability modeling process testified by conducting a simulation. conclusion drawn that due vehicle/engine, besides normal operation mode, union may operate near some safe limits even exceed them, which cause failure flight. Various bound would request various relevant modes thereby control...

A foundation for the engineering of pre-coolers is provided to understand flow and heat transfer characteristics air pre-coolers. Using pre-cooler in combustor Synergistic Air-Breathing Rocket Engine (SABRE) as research object selecting smallest periodic unit model, numerical methods were adopted study field, outlet temperature, total pressure loss, coefficient, power under different number tube rows, pitch, helium/air capacity ratios. The rows increased from 7 15, pitch 1.5 mm 3.5 mm, ratio...

In this paper, an 80-ton thrust liquid rocket engine (hereinafter referred to as LRE) with a gas generator cycle, 5:1 throttling ratio, and integrated flow regulator/gas IFRGG) is analyzed. This LRE can be used during the first stage of launching, second-stage upper-stage space missions, moon/mars low-orbit hovering soft landing, it also various near-space multipurpose flight vehicles. The thermal performance model variable-thrust established, influence main design parameters on optimization...

Electrowetting technology, a microfluidic has attracted more and attention in recent years broad prospects terms of microdroplet drive. In this paper, the dynamic contact angle theory is used to develop numerical model predict droplet behavior internal flow field under electrowetting. particular, based on established computational force balance, process electrowetting analyzed, including perspective pressure variation balance inside droplet. The results show that when alternating current...

A novel dual-heated water and power cogeneration system (WPCS), in which photovoltaic/thermal (PV/T) is used for seawater heating electricity generation, solar collector applied air heating, based on the humidification-dehumidification (HDH) cycle, proposed.Comprehensive performance of WPCS obtained, parametric analysis, from pinch enthalpy difference (PED) within humidifier intensity, are accomplished.It found peak gained-output-ratio (GOR), production cost (WPC) 2.55, 76.32 kg•h -1 15.14...