Przemysław Łukasz Błasiak

• PhD
• Professor (Assistant) at Wrocław University of Science and Technology

This study presents new numerical procedures for simulating cryogenic pulsating heat pipes (PHPs) developed in OpenFOAM. Using a multiphase flow approach, the numerical model incorporates a combination of Lee and Min phase change models and also features conjugate heat transfer between the solid wall and fluid. Turbulence effects are modeled using...

Decarbonising the global energy system involves several critical aspects, such as enhancing energy efficiency, expanding electrification, adopting alternative fuels, and leveraging hydrogen, among other strategies. Cold and cryogenic energy have substantial potential sources, extending beyond liquefied natural gas, as the demand for several alterna...

The Scraped Surface Heat Exchanger (SSHE) is widely used across various industries because of its efficiency in providing thermal treatment of viscous fluids. This article presents a detailed analysis of SSHEs, emphasizing both existing solutions and areas that require further research and development. The literature review was conducted by organiz...

The aim of this paper is to present the results of the experimentally validated numerical code designed for thermal-fluid computations in pulsating heat pipes using CFD techniques. The analysis was carried out using the OpenFOAM software, where an algorithm was developed to simulate multiphase flow with phase change and coupled heat transfer betwee...

Nuclear reactors are very complex units in which many physical processes occur simultaneously. Efficient heat removal from the reactor core is the most important of these processes. Heat is removed from the reactor core via heat conduction, radiation, and convection. Thus, convective heat transfer and its conditions play a crucial role in the opera...

Power-to-Gas technologies are high-capacity systems, which can be used to optimise the use of renewable energy to meet energy demands. Among them, Power-to-Methane (PtM) stands out due to the ease of storage and use of the produced methane. However, its total storing efficiency (Power-to-Methane-to-Power) is likely still low as there are various lo...

The particle deposition rates on the coating surface for three different geometries during the high-pressure cold spray processes were studied and verified in the paper. Analyzes were performed for three different techniques, based on the same de Laval nozzle geometry, but each with a different method of supplying working gas to the system. One cas...

In order to lessen reliance on fossil fuels, a rise in interest in the utilization of fluctuating and intermittent heat sources derived from renewable energy (such as solar thermal, ocean thermal, and geothermal) and waste heat has been observed. These heat sources could be used to generate electricity at relatively low and medium temperatures, for...

The topic of frost formation on the heat exchanger surface has been gaining interest since the late 1940s. Scientists and industrial engineers from many scientific and R&D units around the world have been trying to understand the nature of frosting and implement solutions to prevent such an unwanted phenomenon from having a significant impact on th...

In this paper, the results of numerical investigations on heat transfer in a multi-vane expander (MVE) are reported. MVEs are very interesting for various technological applications because of their advantages (such as, for example, low gas flow capacity and a low expansion ratio). According to a literature study, the heat exchange mechanisms occur...

Thanks to their positive features, i.e., simple design with a small number of moving parts, easy manufacturing, and low production and purchase costs, multi-vane expanders are promising for application in micro-power organic Rankine cycle systems. These expanders are simple in design, small in dimensions, inexpensive, and feature low gas flow capac...

The aim of the article is to numerically model a two-dimensional multiphase flow based on the volume of fluid method (VOF) in a pulsating heat pipe (PHP). The current state of knowledge regarding the modeling of these devices was studied and summarised. The proposed model is developed within open source software, OpenFOAM, based on the predefined s...

The article deals with the experimental and numerical thermal-flow behaviours of a low-temperature Phase Change Material (PCM) used in Thermal Energy Storage (TES) industrial applications. The investigated PCM is a composition that consists of a mixture of paraffin wax capsuled in a melamine-formaldehyde membrane and water, for which a phase change...

The paper presents the experimental investigation of a large scale Pulsating Heat Pipe (PHP) operating under high heating power load of up to 2 kW (56 kW/m^2). Different Filling Ratios (FR) equal to 25, 50 and 75%, the lengths of the adiabatic section 500, 750 and 1000 mm, respectively, and types of working fluid such as: acetone, ethanol and water...

Micro-power domestic organic Rankine cycle (ORC) systems are nowadays of great interest. These systems are considered for combined heat and power (CHP) generation in domestic and distributed applications. The main issues of ORC systems design is selection of the expander and the working fluid. Thanks to their positive features, multi-vane expanders...

Understanding the thermal-flow phenomena which occur in Pulsating Heat Pipes requires sufficient research of a wide spectrum of parameters, which affect the efficiency of the device. For that reason, a special experimental setup was designed, manufactured and successfully operated. The experimental setup allows for the investigation of essential pa...

The work deals with an experimental and numerical analysis on disturbed thermal boundary layer obtained in a heat exchanger by two rotating blades (scrapers). A three-dimensional numerical model of unsteady forced convection in an analyzed device is proposed and taken into consideration. The model allows for the transient nature of the processes oc...

A novel idea of heat transfer enhancement using a U-shaped pulsating tube in a rotating system of coordinates is presented and studied in the paper. The analyzed case consists of a U-shaped tube that rotates around the axis of revolution which is perpendicular to the tube axis. Similar to the classical Pulsating Heat Pipe (PHP), it is composed of a...

This paper concerns the issue of the proper selection of the operating parameters of the fluidised desiccant cooler. Despite the fact that fluidised desiccant cooling technology is being reported in the literature as an efficient way to provide cooling for the purposes of air-conditioning, the improper control of its operation can lead to a signifi...

Micro-power domestic organic Rankine cycle (ORC) systems are nowadays of great interest. These systems are considered for combined heat and power (CHP) generation in domestic and distributed applications. The main issues of ORC systems design is selection of the expander and the working fluid. Thanks to their positive features, multi-vane expanders...

Small- and micro-power ORC systems designed for domestic use by prosumers should be cheap and reliable. The main part of the ORC system cost is the price of heat exchangers and the expander. Multi-vane expanders are positive displacement volumetric machines which are nowadays considered for application in micro-power domestic ORC systems. The multi...

Gas pressure reduction stations are commonly applied to decrease the pressure of natural gas in the transmission pipelines. In such stations, natural gas is expanded in throttling valves without producing any energy. Through the use of expander in natural gas pressure reduction stations, it is possible to recover the pressure energy of the natural...

Heat transfer during scraping of the thermal boundary layer is a commonly encountered phenomenon. The most notable device where scraping heat transfer occurs inherently is a Scraped Surface Heat Exchanger (SSHE), which is widely used in the chemical and food industries. The present study involves an experimental heat transfer investigation into an...

The paper deals with the research of temperature fields in the proximity of heated pipes arranged above each other in natural air convection. The holographic interferometry method was used for the visualization of temperature fields. The experiments were made for pipes having the diameter of 20 mm, length 200 mm at surface temperatures of 40°C, 50°...

Multi-vane expanders are positive displacement volumetric machines which are nowadays considered for application in micro-power domestic ORC systems as promising alternative to micro turbines and other volumetric expanders. The multi-vane expander features very simple design, low gas flow capacity, low expansion ratios, an advantageous ratio of the...

Micro (0.5-10 kW) organic Rankine cycle (ORC) power systems are nowadays considered for domestic power generation. Selection of a suitable expander is one of the most important problems connected with the domestic ORC system design. Volumetric machines or micro-turbines can be adopted as an expander in domestic ORC systems. Scroll and screw expande...

To optimise and to improve heat transfer in heat exchangers, a special construction with rotational blades, called scraped surface heat exchanger (SSHE), can be applied. Despite SSHE are widely used, thermal-flow processes in these devices are still not well understood. The paper presents and describes a method allowing for precise determination of...

In this paper steady state two-dimensional mixed convection heat transfer problem in a lid-driven cavity heated via an uniformly distributed heat flux on the bottom wall is investigated numerically. The lid moves with constant velocity and is kept at low constant temperature, between two ideally thermally insulated vertical walls. A wide range of P...

Dynamic Energy Budget theory describes how organisms obtain energy from environment and use it for maintenance, growth and reproduction. This theory and mathematic model can be used in toxicity assessment of chemicals. One of important model part refers to assimilation and mobilization of reserves. Energy used in this process can be described in un...

Steady state two-dimensional numerical simulation of laminar heat transfer and fluid flow in a scraped surface heat exchanger (SSHE) is presented. Typical SSHE consists of a stator, rotating shaft and scraping blades. Due to symmetry only a quarter of the heat exchanger is modelled. Governing equations for transport of mass, momentum and energy are...