Jianyang Yu

• Ph.D
• associate professor at Harbin Institute of Technology

With the development of aviation technology, aircraft voyage improvement has become an urgent problem to be addressed. Aerial refueling technology has been widely used as an important method for improving endurance. In probe-and-drogue refueling (PDR), the tanker's hose-drogue system is offset by the bow wave generated by the receiver's head. By pr...

The spiral tube heat exchanger has the advantages of stable structure, high space utilization rate, and strong heat transfer ability. Supercritical carbon dioxide (s-CO2) has the advantages of high thermal conductivity, high specific heat capacity, and low viscosity. When the spiral tube heat exchanger uses supercritical carbon dioxide as the heat...

This study is based on two objective functions: minimizing heat transfer entropy production and minimizing viscous dissipation. The reverse-temperature equation and volumetric force sources are derived using variational methods for optimizing convective heat transfer in two-dimensional flows. Linear weights are adjusted to generate velocity and tem...

To address the challenges encountered during a multioperating-point optimization of centrifugal compressor blades, including a large design space, redundant search, limited flexibility, and low optimization efficiency, this paper presents an aerodynamic optimization approach for centrifugal compressor impeller blades based on parameterized free-for...

The cross-wave primary surface recuperator (CW-PSR) is a dependable option as a recuperator for micro gas turbines (MGT). The micro CW-PSR studied in this paper is composed of 171 stacked curved plates, with each plate containing 33 micro heat transfer channels with equivalent diameters of less than 1 mm. In this study, the influence of bending cur...

Since compact structure and centimeter size of solid-oxide fuel cell system equipped with micro gas turbine (SOFC-MGT), the heat of a micro radial-inflow turbine (RIT) is transferred to compressor through wall heat transfer. In this work, an integrated design method considering wall heat transfer was proposed to develop an efficient micro-RIT appli...

To eliminate the deficiency arising from the whole machine test with simplified cross-wavy (SCC) in investigating the impact of inlet and outlet structure and heat transfer characteristics of different channels, the heat exchange cell (HEC) is employed to explore the heat transfer and flow mechanism of the annular cross-wavy primary surface recuper...

With the development of artificial intelligence, machine learning technique has been applied in turbomachinery optimization. However, the performance of a classic machine learning method largely depends on the quantity and quality of data samples. Due to the high cost of computational fluid dynamics models, a small sample size may restrict the reli...

Air refueling technology can improve the range, combat time, and dispatch efficiency of combat aircraft. Among them, soft air refueling has become the most widely used air refueling method in the air forces of various countries due to its mature and reliable advantages, such as small size, simple structure, easy disassembly and assembly, and good c...

The key to an efficient parameterization method in airfoil design optimization is to control aerodynamic shape accurately with as few parameters as possible. Due to the disadvantages of traditional parameterization methods, such as plentiful variables and inflexible deformation, the Free-form Deformation (FFD) technique is getting attention. This w...

Two novel tip modeling methods are proposed in this paper. One novel tip is established by the mathematical method and the other is generated by the B-spline surface. And the genetic algorithm, the orthogonal design and the Kriging model are applied to optimize two kinds of novel tips numerically. The optimal mathematical tip and the optimal B-spli...

In this paper, the effects of dielectric barrier discharge (DBD) plasma actuators (PAs) on the leakage flow structures and loss in a turbine cascade have been experimental studied. Two group cases have been conducted to evaluate the performance of the DBD plasma actuators and its effect varied with the attack of angles (α). By measuring the static...

Vortex generator jets usually use a circular hole. The hole exit shape is also an important parameter, so the change of the shape will have a significant influence on the control effect of the compressor. In this article, the optimization design of the hole exit shape is studied in order to find the optimal geometry. The 2D hole exit shape is repre...

With the development of modern aero-engine, the compressor is required to achieve higher performance such as transonic operation, high stage pressure ratio and efficiency. At present, the traditional blade design methods have the disadvantage of highly relying on designer's experience and heavy computational burden. In order to reduce design variab...

When a solid sphere exits water at a given velocity, the liquid column is pulled out of a liquid reservoir. The present study focuses on the dynamic deformation of the liquid column and on the identification of the liquid column regime on the Weber number and dimensionless time (We-t*) map. The three-dimensional model of water exit has been establi...

Three kinds of rotor tip configurations have been investigated numerically in the LISA 1.5-stage turbine, including the flat tip, the honeycomb tip and the honeycomb tip with injection. The effect of the cavity depth and the injection mass flow rate on the turbine performance is studied in detail, evaluated by the isentropic total-to-total efficien...

In the present paper, the Nested Sparse-grid Stochastic Collocation Method (NSSCM) is utilized to investigate the uncertain effects of stochastic blade stagger angles on the aerodynamic performance of the turbine blade. Two typical test functions are used to validate the calculation efficiency and precision of the NSSCM in Uncertainty Quantificatio...

The bending clearance design method is applied for the aerodynamic optimization by using the Kriging model and Genetic Algorithm. To validate the effects of the clearance shape and the deformation coefficient on the TLF suppression, the baseline case and other four modified cases have been experimentally and numerically investigated in a low speed...

The geometric parameters of the composite honeycomb tip have been extracted and optimized using Kriging model and genetic algorithm numerically. A total of 36 sets of input-response combination are included from full factor design. The Kriging model for the tip leakage mass flow rate is established and assessed by leave-one-out cross validation. Th...

The effect of the cooling injection orientation and position on the tip leakage flow has been studied numerically in a honeycomb-tip turbine cascade. The injected fluid enters each honeycomb cavity through the bottom pipe at a fixed incident angle. The effect of the relative casing motion with six casing speeds is considered. The Reynolds-averaged...

The dielectric barrier discharge (DBD) plasma actuator, in which electrodes are asymmetric arranged, has already demonstrated its ability in flow control. In the present work, the configuration of multiple plasma actuators is placed at the suction side of the cascade top to realize the tip leakage control. However, massive configurations appear whe...

The effect of five arrangements of the double-slot injections on the leakage flow control is studied in a honeycomb-tip turbine cascade numerically. The honeycomb tip is covered with 67 intact honeycomb cavities, since the uneven tip is wearable and the cavity vortex could realize the aerodynamic sealing for the leakage flow. Then in the present st...

The concept of circumferential bending clearance based on Gauss Bimodal Function is proposed to suppress tip leakage flow (TLF) in a highly-loaded turbine cascade. In this method, a new vortex (BV) can be induced to mix with TLV in the middle of tip region and block the development of tip leakage vortex (TLV). Since the blocking effect divides the...

In this paper, the effects of multiple dielectric barrier discharge (DBD) plasma actuators on the leakage flow structures and loss conditions have been numerically studied in an axial turbine cascade. Kriging surrogate model is adopted to obtain the optimal cases. The physical mechanism of flow structures inside the gap that control leakage flow is...

Tip geometry modification is frequently used to suppress the tip leakage flow in the turbine cascade however a universally beneficial tip geometry modification design has not been fully discovered. In this paper, the two-surface coupling arbitrary blade tip design method in three-dimensional physical space which satisfies the simple trigonometric f...

Equipping a slice of air film on a vehicle's exterior can realize the goal of load reduction and attitude control in the vertical water-emerging process. Similar to ventilated cavity, the performance of this air film depends on the venting structures and their arrangements. Based on the simulation of vehicle's water-emerging processes with exhaust,...

Many uncertain factors in the water-emerging process of a vehicle influence the taking effect of the air film around its shoulder in the load reduction and attitude control. Assuming the launch parameters (launch depth, vehicle velocity, and chamber pressure) as sources of uncertainties, the uncertain evolution process of the air film in the water-...

In this paper, the three-dimensional water exit of a sphere with different vertical velocities is investigated numerically using the lattice Boltzmann method (LBM). In this method, the liquid-gas two-phase flow is simplified as a single-phase free surface flow. To capture the free surface, a mass tracking algorithm is incorporated into the LBM. The...

The influence of different arbitrary blade tip shapes on restraining the tip leakage flow in a highly loaded turbine cascade has been numerically studied. A combined method of establishing and optimizing the arbitrary blade tip shape is proposed by using B-spline surface modeling, Kriging model and genetic optimization algorithm. The results show t...

In the present work, an improved dielectric barrier discharge (DBD) plasma model is applied to a highly-loaded turbine cascade to numerically study its effect on suppressing tip leakage flow. First, a parameter identification system is established using the Kriging model and genetic algorithm. The simplified model is then improved based on this par...

In this paper, the control mechanism of the honeycomb tip structure on the tip leakage flow of a turbine cascade is studied experimentally and numerically, and the sensitivity of tip leakage flow characteristics to different clearance heights from 0.5% to 2% based on the blade span are mainly discussed. A flat tip is considered as a comparative cas...

Vertical emerging processes of an underwater vehicle with one and two rows of holes exhaust are numerically simulated to investigate its influence on the evolution of air film and flow field around vehicle’s exterior. Results show that when compared with the single-row hole case, exhausting with two rows of holes brings about the “reverse flow” whi...

One of the important ways of improving compressor performance is to control three-dimensional (3D) separations which are related to the end-wall cross flow and corner separation. End-wall VGJs has been applied on the leading edge of the blade within a high subsonic compressor cascade to control the separation. Flow-control experiments are conducted...

The dielectric barrier discharge (DBD) plasma actuator, in which electrodes are asymmetric arranged, has already demonstrated its ability in flow control. In the present work, the configuration of DBD plasma actuator defined as DBD-vortex generator (VGs), which can induce streamwise vortices, has been employed in the flow control of the inclined je...

The vertically launched underwater vehicle always suffers various hydrodynamic disturbances in its water-emerging process due to the uncertainty of the launch platform motion. Based on the nested sparse grid based stochastic collocation method (NSSCM) and nonintrusive polynomial chaos method, the effect of uncertainty of platform velocity and yaw a...

In order to explore the control mechanism of vortex generator jet, which is located in the passage (PVGJ), on the separation flow, the influence of the pitch angle, skew angle, locations and jet-to-inflow ratio are studied using numerical methods in a high subsonic compressor cascade. The changing of the flow pattern is also analyzed in detail. The...

Two innovative composite tip structures that combine a honeycomb with a prismoid or spherical bottom have been proposed to actively control the tip leakage flow in a turbine cascade. The mechanisms of inhibiting leakage flow are mainly analyzed from the aspects of detailed flow field, vortex structures, and turbulent kinetic energy dissipation. The...

The effects of the cooling injection with various injection positions and angles on the tip leakage flow have been numerically studied in an axial turbine cascade with honeycomb tip. The coolant is injected through the bottom hole into each honeycomb cavity and coupled with the internal vortices to obstruct the leakage flow. Tip leakage mass flow r...

Pressure-equalizing film is a slice of air film generated through exhausting and attached to the exterior of vehicle with nearly uniform inner pressure. This paper established a numerical approach to investigate the effect of single and double rows of venting holes on the evaluation of air film along vehicle's exterior, at the same time its influen...

A vertically moving underwater vehicle with an air film attached to its exterior can significantly weaken the hydrodynamic disturbances caused by launch conditions. To quantify the ability of a pressure-equalizing film to improve the trajectory and attitude robustness of vehicles under an uncertain platform velocity input, the response surface mode...

Pressure-equalizing film is a slice of air layer attached to vehicle exterior with nearly uniform inside pressure, similar to ventilated cavity in composition; it is generated through exhaust process of the inside air chamber as vehicle emerges from deep water, and can reduce the lateral force and pitching moment that vertical launched underwater v...

This paper reports the large eddy simulations of the effects of a saw-tooth plasma actuator and the laidback fan-shaped hole on the film cooling flow characteristics, and the numerical results are compared with a corresponding standard configuration (cylindrical hole without the saw-tooth plasma actuator). For this numerical research, the saw-tooth...

This paper presents results on a saw tooth plasma actuator for the inducement of flow topology and the improvement of flat plate film cooling efficiency. A phenomenological plasma model is constructed to generate the three-dimensional plasma force vectors of the saw tooth plasma actuator. The dynamics of airflow induced by the saw tooth plasma actu...

In this work, the dielectric-barrier-discharge plasma actuator was employed to study the flow structures induced by the plasma actuator over a flat plate and a wall-mounted hump. A phenomenological dielectric-barrier-discharge plasma model which regarded the plasma effect as the body force was implemented into the Navier-Stokes equations solved by...

Pressure-equalizing exhaust is an effective flow control technique to improve the hydrody-namic characteristics of underwater vehicles and to inhibit their pitching moment. In this paper, numerical simulation is conducted to study the underwater vertical movement process of an underwater vehicle with pressure-equalizing exhaust. The variation of th...

Four different Subgrid-Scale models were employed in the study of flow over a wall-mounted hump and then the most capable one was used in flow control with the DBD plasma in this work. The results show that the WALE model and the KET model demonstrate good qualitative agreement with the experimental data The Smagorinsky-Lilly displays some shortage...

A new method using combined-jets is proposed to control the end-wall secondary flow in a high speed compressor cascade with inlet Mach number of 0.67. The end-wall vortex generator jet (VGJ) near the leading edge could enhance the fluid exchange between the end-wall boundary layer and the mainstream, thus suppressing the cross flow and reducing the...

An investigation into the flow characteristic on a flat plate induced by an unsteady plasma was conducted with the methods of direct numerical simulations (DNS). A simplified model of dielectric barrier discharge (DBD) plasma was applied and its parameters were calibrated with the experimental results. In the simulations, effects of the actuation f...

In this paper, numerical simulation of the whole structure of a half flush-mounted S-shaped air-intake and the rear fan stage was conducted for investigating the impact of air-intake exit distortion on the fan-stage performance. Considering substantial boundary layer ingesting, a scheme of blowing control imposed near the first bend of the inlet wh...

A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid dynamics. The effects of the applied voltage on the distribution of velocity and temperature in initially static air are parametrical...

Particle image velocimetry experiments and simulations were conducted in this study to clarify the influence of the DBD plasma actuator on the flow over a flat plate. The result shows that the actuator not only effectively leads to a local rise in near-wall velocity, but also efficiently causes a decrease in the displacement thickness of the bounda...

The local losses mechanisms study of three low-speed compressor cascades with the different turning angle were presented. The results indicate that, the separation corner is an accumulation zone of low energy fluid rather than high local loss zone. While in the outer of the separation, high local losses are generated by the serious shear effects be...

In order to explore the influence mechanism to the aerodynamic performance and the near-wall flow structure on a high load compressor cascade with slots injection, the cascade near-wall flow structure and flow losses in outlet were investigated experimentally on the high-loading compound lean compressor cascades with/without slots under the design...

In order to explore the influence of launch depth on the mechanism of engine underwater ignition flow characteristics, the unsteady evolution of gas-water two-phase flow field about test nozzle was studied numerically under different water depths when the engine ignition. The results show that since strong shear flow in the gas bubble are blocked t...